If it's not bug 1717878 then next please attach a system log of the bug:
1. Reproduce the the login loop again.
2. Reboot into recovery.
3. Run:
journalctl -b-1 > prevboot.txt
4. Somehow copy the resulting text file off the machine and attach it here.
If it's not bug 1717878 then next please attach a system log of the bug:
1. Reproduce the the login loop again.
2. Reboot into recovery.
3. Run:
journalctl -b-1 > prevboot.txt
4. Somehow copy the resulting text file off the machine and attach it here.