Gauntlet 5
I was playing the Ultimate Team Gauntlet 5 and none of the matches were counting! At the end of each match, a message appeared saying "Unable to connect to Ultimate Team. You will be returned to the main menu." So I would exit UT and none of the matches were registered!
In the last match of the challenge, I disconnected because the internet went down, and since then I haven't been able to log into Ultimate Team!! The same message keeps appearing: "Unable to connect to Ultimate Team. You will return to the main menu," and I'm returned to the main menu without even entering Ultimate Team.
If you can log into the web app or companion app, go to Squads, create a new one with no players, and delete all the squads you had.
Do that and then log into UT, it'll work! I hope it works for you.