I am having the same problem. Everything was working okay then suddenly it stopped working. Here is a list of everything I have tried so far:
Reset game - hard reset xbox - reset router - reset modem - Cleared cache - unlinked and relinked EA account - uninstalled and reinstalled the game - deleted local account data - ran on wired connection - cleared MAC address - used manual DNS settings.
I ran a mobile hotspot and this completely resolved the issue which leads me to believe there is a specific problem between some ISPs and EA servers, but something must have changed on EA's end within the last couple of days for this to happen as I've never ran into this problem before.