Okay good news actually, I finally verified an account with an EU sim cards (didn't work before cause I didn't enter my country code) and that account didn't get banned! So I guess the fact that I verified an account with a US card on a EU proxy banned it ? Anyway, thank you guys. If that didn't worked, I would have change my proxies (because flagged) but for now I'll keep them as the problem seems to be fixed.