Try this if you have input lag
A lot of people, incuding myself, have been struggling with input lag lately. My location probably does not help (southerneast Europe), but there are so many factors affecting input lag that I can go from a perfect match to an unplayable one on the same session.
I play only pvp league divisions on PS5 and like many of you I have a good wired connection, good router, my console prioritised, cat6+ ethernet cable, no problems in other online games, etc...
I have tried a lot of suggestions to improve input lag, but no luck... until I saw one suggestion in an old thread's comment, some days ago.
It simply suggested to "turn off cross play" from the general game settings. So I gave it a try.
Cannot explain how blocking other platform players has helped with my matchimaking and ultimately my input lag, but it simply works. Maybe cross platform matches add some input lag? I cannot be sure...
Of course, it will now take a bit more time to find opponents (especially if you combine it with same setting for semi assist, search nearby only for matchmaking and play on unpopular hours like I do), but input lag has been significantly improved for me since changing this setting.
I went from most matches being almost unplayable due to very heavy input lag lately, to all matches now being playable at least and perfectly smooth if you are a bit lucky with matchmaking (I had some perfect matches with the previous setting too, but now seems more likely).
I have searched a lot on this issue and there is no permanent fix, especially for division matches. If you have optimized your network, input lag is ultimately affected by your location and time you play - these two factors will affect your matchmaking (location of your opponent) and all these come down to which server is picked for the game. Some servers are simply bad or loaded or so far away, some are better.