Hey There! I did find it a little suspicous because I do purchase the Season 4 Battle pass literally two days before this incident... I do have an Xbox One S also. So back to the main reason of thsi post! I did manage to call/ live chat with EA, and they said to do these things...
+ Reset your system but keep your games saved data ( that did not work for me)
+ Uninstall / Reinstall the game on the system (that did not work for me)
+Reset my EA Password.(THIS DID! ALTHOUGH IM SURE THERE WERE OTHER FACTORS)
Once they asked me to reset my EA Account, they asked for my email and the corresponding email I thought I had used was actually wrong for the EA Account. Make sure that you guys do not have another system used as your "Home XBOX" I believe this played a role in the game saying "This account is invalid. So after that, they sent a code to the ACTUAL Email that was linked to it, I sent them that code, then they can change the email for you and reset the actual game for you. I believe this process did work...
This process lasted at least 6-8 hours the same day it was not working for me because I said I would stop trying so hard to get the game to work, Patience helped and then I was able to sign in. And now Im completing my Season 4 battlepass! and getting more season 4 wins!!! 🙂