The “getting stuck at 100%” bug reappeared for me on my XA2 Ultra.
I experienced this when I updated to 4.2.0 ([Release notes] Verla 4.2.0 - #201 by Simerax).
Basically the Progress gets stuck at 100% forever. Restarting the device worked back on 4.2.0 and also seems to work on 4.4.0.68
I did not experience this problem in any release between those two.
Edit: The Device got updated from 4.4.0.64 to 4.4.0.68