I am unable to collect/advance my arbiter missions. I had been stuck on the “take two great hall bonuses to 6” mission for a while. Completed it last night and collected the reward, it immediately rewarded the next mission which I collected, then immediately rewarded the following mission, but now I can’t collect the current completed mission ("Unlock 3 T4 masteries"). I get this message every time I try to collect. Have tried restarting and reinstalling but nothing allows me to collect and advance to next mission. Running iOS on iPad Air, all software up to date.