SBC soft ban? completing bronze upgrades

I have been grinding the gallery, spent 400k coins on bronze packs, saving all the players and quick selling the rest, all the bronzes go into bronze upgrade SBCs to get some silvers for the club to get more gallery progress, doing this for a while and now out of no where i get hit with a lost connection message and get kicked from ultimate team? Is this a soft ban? why do repeatable SBCs exist if theres bans like this in place. I am not using 3rd party tools either... now with ultimate scream tokens, i am worried that ill miss out on the ones tied to SBCs therefore missing out on rewards.

Please help