I’ve found this thread in the Manjaro forum:
https://forum.manjaro.org/t/lightdm-resetting-when-used-with-bspwm-after-updating/46764
Reading the 1st sentence in the fist entry to this thread, the symptoms of the problem are the same/very similar. In the last entry, the user suspects a .Xauthority file with wrong content as the cause and he proposes these 4 steps, when at the login window and after upgrading to *.12-1:
0. stop lightdm service
1. remove the .Xauthority file
2. start any DE with startx / xinit and stop it
4. start lightdm service
I performed those steps, but, at least with me, the problem remains.
In this thread:
there is a link to:
https://gitlab.freedesktop.org/xorg/xserver/-/issues/1195
They suspect, that an NVIDIA GPU and the corresponding driver might cause the problem (iicc), and no solution up to now.
But in my case, the Endeavour VM uses the “Intel HD Graphics 530” HW of the KVM-host transparently with the “Red Hat QXL paravirtual Graphics Card” driver. No NVIDIA GPU.
The solution is always the workaround to downgrade the xserver to *.11-1, which is unsatisfying.
Regards. / Hilmar.