First of all, today her task menu has reappeared this morning with the daily reset. So from my understanding, a switch to english and a daily reset solves the issue; if it helps track down this bug.
I do know most off her tasks for that day by knowing what tasks she had on the second day of the bug (yesterday).
First day : one task blindly completed doing pvp Slot1 or Slot2. No english switch, didnt knew
Slot1 unsure, Slot2 unsure, Slot3 10 battles with troops from same kingdom, Slot4 4 explores in adana.
Second day : one task blindly completed opening glory chest, rewards 3 glory keys. So task was 10 glory chests. English switch after that (thanks to gunthaar).
Slot1 8 kills with hero weapon, Slot2 open 10 glory chests, Slot3 10 battles with troops from the same kingdom, Slot4 4 explores in adana.
Day one tasks are just deductions made of what she had left on day two because not completed day one, Slot3 and Slot4 are 100% accurate. My personal guess for Slot1 is pvp related task (10/25 victories, 40 trophies or 3 revenges) and for Slot2 it was probably open 10 glory chest (she does not remember if she opened glory chests that day,sorry).
If you still need it her invite account is : SYLVIANE_E5VB
Thanks for taking the time
I hope that will help
And the more important, Happy New Year