Hi bro, i hope i'll manage to help you (in case you didn't manage to fix it yet). I had the exact same issue as you. Sometimes it'd magically work, but most of the time i wouldn't be able to play any match at all, whatever the game mode might be. I tried everything: launch the game multiple times, uninstall and reinstall the game, the anti-cheat. But at some point it just stopped working. I opened the game 15 different times, and those 15 times were not successful, i couldn't play. I could go through the menus, the game didn't have any problem, but it couldn't load a single match.
I asked an AI, and it told me it was probably the cache that was corrupted, or something. Try to find the folder named "EA SPORTS FC 26". For me, it was located in the AppData folder. It contains folders like replays, umcache and other things. Rename that folder (the EA SPORTS FC 26 one) with what you want. When you'll launch the game next time, it won't manage to detect this folder, and hence will create a new one from scratch. That solved the issue for me.
If you already tried that and it didn't work, then i don't know what you could do. Either way, i hope it'll help you. And if not, i hope you'll manage to find a solution at some point. Good luck !
