Hi to all
I am an Xbox one player and have had the same problem occur intermittently. I usually get the error 721 and can't connect after returning to the xbox live home screen without quitting the game, turning off the console (not the power). Later, when I turn on the console and resume the game, this error pops up. It has happened to me before the SEPT update. My fix has been to return to the xbox live home screen, quit SWBF2 and relaunch. This has always fixed the problem for me. Now when I quit the game, I always quit from the XB live home screen and have had no further problems with this error. I play twice a day nearly every day afternoon & night (Yeah, I know I should get a life!!! LoL). My region is Australia.
There are a few questions that I would like to ask you all.
1. What regions are you playing in.
2. Do you have the same problem if you try a different ping site.
3. What Xbox console are you using - Xbox one, one S or one X.
4. Are you using standard or modded controllers.
5. Have you tried the usual - deleting save game files (console and XB Live) or changing profiles (even to a friend's).
I have mentioned Profile in the last question because I know some people have had a problem with game crashes and not being able to connect because of a corrupt XB live profile. The fix was to delete your profile and set up a new one with exactly the same details as the deleted one.
With deleting save game files - select delete everywhere. This will delete both files but not the Data file on the EA server so your credit, milestones, ranking etc will not be affected. You will, however, have to reselect your ability cards for every trooper, hero and vehicle. You do not lose the cards you have earned but how you applied them. I'm not sure but I think the same applies for your Blaster upgrades.
I don't expect everyone to reply to me directly, Just put the questions out there. Maybe one of the answers might be a fix for you.
Just so you know, I have no affiliation with EA. Just another player trying to help.