DP connector re-enumeration causes display configuration to not persist
Recreating a bug from 2017 here (https://bugzilla.gnome.org/show_bug.cgi?id=790805)
*Benjamin Berg 2017-11-24 20:49:57 UTC
It seems like the DP port number regularly change depending on initialisation and actions done by the user. As an example. I earlier rebooted my machine, and the display moved from DP-6 to DP-3 after a reboot. When e.g. plugging in the monitor while it was on DP-6, DP-7 would also appear as the monitor supports daisy chaining.
I am not sure which port types may be enumerated randomly by the kernel. In general, it seems to me though that usually the right thing is to ignore the connector while looking for existing configurations and only using it as a fallback would be a good approach.
I have seen some other odd things. Some of them might be related to #766469.*
I have another user (RHEL 8) with 2 external displays (one standard rotation, one 90 degrees rotation), and every time the system is undocked and docked, the 90-degree display is reset.
For the RHEL: 8 machine:
mutter-3.28.3-19.el8_0.x86_64 kernel: 4.18.0-144.el8.x86_64