The multi-monitor layout is different each login on Wayland. This affects a number of related settings: position, size (zoom), desktop background, panel configuration etc.
The cause appears to be the name assignment in `~/.config/plasmashellrc`.
On my system, the laptop screen (eDP-1) is always screen 0. The other displays are the same physical displays on the same physical ports, but the DP-n number changes each time.
STEPS TO REPRODUCE
1. Login to Wayland and configure screen layout
2. Logout + reboot
3. Login to Wayland
The screen layout has changed
The screen layout is the same
(available in About System)
KDE Plasma Version: 5.24.4
KDE Frameworks Version: 5.92.0
Qt Version: 5.15.2+kde294
The laptop has hybrid Intel/Nvidia graphics. The Intel UHD graphics drive the primary laptop display, the external monitors are connected via a Thunderbolt dock, which is routed via the Nvidia chip.
This may be related to bug 427278 - although that was for X11 & VNC, and is resolved.
This was supposed to be fully finally fixed in Bug 427278. I guess there's at least one edge case we missed. :(
*** Bug 456761 has been marked as a duplicate of this bug. ***
the connector names come from KScreen; moving there.
*** This bug has been marked as a duplicate of bug 450068 ***