Is KOF XV's matchmaking still broken?

Yes.

It's been broken since release day, February 17th 2022 (SteamDB page).

SNK announced crossplay coming in 2023 at EVO 2022 (2022-08-07).
Players hope this will include the final fix for the matchmaking, but SNK themselves have never explicitly stated that it would.

2022-08-29 (5 months after release): Most recent update from the developers - Interview from gamersunite.mx at EVO 2022

gamersunite.mx: Matchmaking in KOF XV has been one of the biggest complaints from the community, what are you doing about it, do you think crossplay will help?

Yasuyuki Oda, Chief Producer: Unfortunately there are certain parts of this problem that we have not been able to reproduce in the studio, because there are so many factors in this.
For example, on our end there are some things that we can't reproduce because they just don't happen. For this reason there are certain points that we are still investigating and trying to improve.
As a company, there are many things that we cannot reproduce in the development environment and others that are very specific to certain regions, such as the internet provider or the router, so there are certain things that are impossible to solve without having certain data.

Kaito Soranaka, Game Director: We have already identified part of the factors of the matchmaking problem, now we are trying to solve it part by part, for example, add this or change that in order to improve the system.

Latest improvement - August 8th 2022 (5 months after release)

Patch Ver.1.40
Ranked Matchmaking・Now easier to find players of a similar rank to oneself when searching "Any" for Player Strength.

Some users have reported much quicker waiting times (seconds), but some issues persist, mainly waiting times get back to being long after connection errors or refusing a match.
Others have reported no changes in their waiting times, still in the 20+ minutes range.

Discussion on reddit - /r/kof - Did you notice any changes to matchmaking time?

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What is going on?

Ever since The King of Fighters XV has been released, a large amount of players are unable to find opponents online or have to wait up to more than 30 minutes when queuing up for casual or ranked games.
This happens on PC, PS4, PS5, and Xbox.

Players paid $60 for the game and are unable to match up with opponents online, and therefore unable to play the game at all.
SNK, the game's developer, has remained silent regarding any progress on this issue or its priority and there is no fix in sight.
This is unacceptable.

The game is effectively non-functional for those users, as they're unable to play online.

Those that are patient enough to sometimes wait over 30 minutes to get a match often report ending up getting matched up with unplayable connections (200ms+ ping, 5+ rollback frames).
This happens even if you restrict your search settings to only the highest quality connections.

Even amongst those having no trouble finding opponents, users often mention repeatedly facing the same handful of players online.

More and more players are giving up on the game, and SNK is killing its own game by taking no action.
In the long run this means less players to play against, as well as less revenue for SNK as the player count keeps shrinking and therefore less people will be buying additional content.
Everyone loses here.

The longer it takes for the matchmaking to be fixed, the more players will abandon the game.

Is it because the player count is low?

No.
As of April 2022, KOF XV has daily player count peaks at around ~1500 users.
This is a solid number by fighting game standards and is more than enough to find opponents in games with similar user counts such as Guilty Gear Strive, Street Fighter V, and Tekken 7.

In the meantime, SNK has had time to release several patches and extra content, none of which addressed the matchmaking problems:

While these fixes and additions are appreciated, they serve close to no purpose for the share of users that aren't able to face human opponents via matchmaking.

Here is the average reply to patchnote releases:

matchmaking? matchmaking? matchmaking fix?

What has SNK said and done?

Here is a timeline of the events:

February 17th 2022
Game releases.

February 28th 2022 (11 days after release)
SNK acknowledges the issue on Steam forums:

[Steam] Addressing some issues

This is what we're currently investigating:

-One-sided rollback
-Lag spikes
-Fair Play Score issues
-Matchmaking issues
-General crashes
-Visual issues on PC
-Keyboard problems

Fabruary/March
An SNK representative mentions work being done on the matchmaking issue in Maximilian Dood's twitch steam chat.
Maximilian Dood is a fighting game influencer with over 1.4M YouTube subscribers and 1M Twitch followers.
Some would argue a twitch chatroom isn't the way to communicate such issue with the community due to its ephemeral nature.

March 23rd 2022 (34 days after release)
[Steam] Have They Fixed The Online Connectivity Issues Yet? Reply #29 - SNK Dev

Hello there,

We are investigating the issues but with the PC, the reasons can multiply exponentially, it can be PC specs, internet connection, graphics, antivirus, firewalls, in-game search filter settings, etc., and we need to rule out the user-specific conditions.

The more information and details that you can provide, it makes easier for us to actually spot the issue.

Best regards, SNK Dev C

Users then proceeded to provide detailed informations (e.g 1, 2, 3), and we haven't heard anything back since. We don't know if the provided information was useful for them, or if they need anything else because they haven't said anything about it.

August 8th 2022 (5 months after release)

Patch Ver.1.40
Ranked Matchmaking・Now easier to find players of a similar rank to oneself when searching "Any" for Player Strength.

Some users have reported much quicker waiting times (seconds), but some issues persist, mainly waiting times get back to being long after connection errors or refusing a match.

What do players expect from SNK?

The KOF XV playerbase hopes to have a working matchmaking engine soon.
SNK can help by doing the following:

Frequently Asked Questions

Do we know where the issue stems from?

No.
So far the community has been unable to pinpoint an exact, reproducible way of making the matchmaking issue occur. It happens to some users while it doesn't to some others.
The problem has happened to players of all sorts of ranks, hardware, and geographical region.

Is it because your region has a low player count?

No.
The long queuing times have been observed across the most densely populated regions (NA, EU, SA) at peak hours (5pm - midnight local time).

Is it because users aren't using "Any rank", "Any connection level", or "Any region" search settings?

No.
Users have tried expanding their search settings and it makes no difference with regards to matchmaking wait times.

Have you tried training standby instead of regular queuing?

Yes.
It makes no difference.

Are you sure it's not just on PC? My friend plays on PS4 and has no issues.

[Steam] Player base and PC performance

I got the ps4 version but am sorry to say it's very hard to find a game. Waited a good time on many occasions with even lowest possible settings and got to only play 2 matches.
[/r/fighters] KOF XV matchmaking problem
am facing the same Matchmaking issues. I’m in EU PS4.
[/r/kof]The matchmaking system has a problem
I play on Playstation, and every time I try to play ranked, it will only matchmaking me with the same person.
If I wait a while and try it again, it will find someone else, but after matches with this person and queue again, the matchmaking system will match me with this same person again and again. This is so terrible.
@fmac95
Glad to see people highlighting the matchmaking problems in KOF. Games outright unplayable sometimes on PS4. When you’re actually IN the game it’s fantastic, but outside its… Something.
@ponk3e
Kof xv matchmaking is a joke on ps4
[gamefaqs] matchmaking issues
ps4 match making since the official release day has gotten way way worse
in fact it seems to have gotten worse the longer its gone on every day seems to have gotten s***tier and s***tier to the point where i no longer wanna play now
there's a issue there for sure

Is it because this is SNK's first time implementing rollback netcode?

No.
Rollback is a way of implementing networking logic once you're in game, fighting against your opponent.
The matchmaking engine comes into play before that, its purpose is to find two players and offer them to play against each other. Whether the in-game networking logic is delay or rollback based has no impact on the implementation of a matchmaking engine.

Is it because SNK's dev team is small and a matchmaking engine is difficult to implement?

A working matchmaking engine is the absolute core and basic functionality of a PvP online game.
Team size should not come into play as to whether or not a developer releases their game with a working matchmaking engine for an online game.
If you release your online game with a matchmaking that doesn't work, your game is effectively non-functional.

Matchmaking engines are a solved problem, and have been for decades. KOF XV's matchmaking uses the following parameters: user score (match leavers), user rank, connection quality level, user region – none of which require any special kind of implementation logic.

A matchmaking engine could have been implemented entirely from scratch between release day and the date this website was first published (2 months).
(I'm a software developer if ever it helps make this answer valid).

Is it because of your firewall, antivirus, or port forwarding settings?

No.
Disabling those doesn't help.
Users having matchmaking issues on KOF XV have no online issues in any other games at all.

Can't you play room matches instead of using the casual/ranked queues?

It appears that the room finder is also broken.
People queuing from NA or EU will end up finding rooms with opponents that have 300ms+ ping with usernames using alphabets from Asian countries.

Can't you find some people on discord to play with?

Discord:

Yes we can, but don't you think that it would be nice in the year 2022 to open up the game, press a button to queue up, and find an opponent at your level within minutes?
Discord currently is the only reliable way to find games, but you will have to be lucky enough to find someone that is both available and also at your player level.

I have been playing KOF XV and have had no issues finding matches.

I am genuinely happy for you, but unfortunately this is not what a major part of the playerbase has had the chance to experience.
I promise none of us are making up this matchmaking problem.

If you think about it, when SNK fixes this issue, you'll have even more people to play against with. Please share our pain, join us in making this issue widely known in hopes that it gets fixed.

I want to help, What can I do?

In short, be loud, keep talking publicly about this issue as much as you can until SNK fixes the matchmaking.

Social media

Try and get attention from some of these official accounts:

Ask them how far along they are with the matchmaking fix: Do they have a timeframe? Do they need community help (providing info)? Can they provide a progress update?
You paid $60, you deserve to have answers as to why you're still not able to play online after several months.

Influencers:

Fighting game influencers could be the force that helps players get heard on this issue.
Kindly ask some of your favorite ones if they would consider helping everyone out by covering this problem on their twitter, YouTube, or Twitch.
A few names:

User forums

Post regular new threads about the matchmaking on these forums, comments and share your experience when you see someone else discuss the topic too.

Are you sure it's not just you?

Yeah I'm sure.

and there's a lot more.

The sad thing is, if you pay attention, everyone complaining about the matchmaking still stresses the fact that the game itself is great.
We really just want to be able to play it.

I'm really excited about the game, should I still try and buy it?

The game itself is great, its matchmaking doesn't work however.
I would strongly recommend against buying it with the matchmaking in its current state.
If you really want to try your luck on PC, buy it, instantly queue up for matchmaking and see if you're experiencing long wait times – you can refund the game as long as your playtime is under 2 hours.