I messed mine up trying to speed up phone for wars ,,what messed mine up was in settings, goto developer options,,and make sure ur keeping resent activities, i turned mine off and it prevented trading,i made it so my phone didnt keep activities,henceforth it stopped trading. I found 3 other ppl that had this problem and this fixed,sry nottech savvy, obviously and great at posting, just hoping to help some ppl
Tl;dr(for the lazy folks) Go to developer options and and turn off "do not keep activities" This is what it looks like on android.