How can I fix this?

I’ve having difficulties playing any game mode on ultimate team. I’ve never had this problem before but half of the games I play it disconnects me from it and it’s caused me to lose games on fut champs. I don’t know how to fix it and it’s i physically can’t play anything without getting disconnected. It says something like I have poor connection to the opposition but my wifi is great. Also, one game of fut champs I lost because I had a full black screen and couldn’t even see my players.