Created attachment 156142 [details]
error log upon screen turning on
I know this is probably related to https://bugs.kde.org/show_bug.cgi?id=353975 however I feel like I cannot be certain it is ConnectorId being messed up upon screen being turned off then turned on. So I would like to report it here just in case this is another bug:
I am running on an AMD 5700xt with two identical LG 4k monitors (A and B, with A being the primary on the left side) connected through display port. I noticed that (almost 100% reliably) each time when the monitor being shut off then turned on (either manually or through inactivity), the primary (always this one) display A will lose wallpaper (showing a black desktop) and right-click does not pop up the context menu. However mouse cursor can move into this screen just fine.
Additionally, I noticed that if I set monitor B as primary and switch it to "right" side in system settings, I can no longer observe this issue. So it likely has something to do with the screen positions and order.
I am also attaching the log immediately following the screen turning on.
STEPS TO REPRODUCE
1. turn off both screen
2. turn on them both
Primary display lost wallpaper showing blank screen (but panel is visible and operable)
Showing desktop normally
KDE Plasma Version: 5.26.5
I want to make a correction: I just tested again by switching B into primary and now after being turned on B shows a black screen. So this issue appears only affect whichever is being set as the **primary** screen.
Also want to add that I tested again using KDE Neon unstable, version 5.27.80, using exactly the same configuration as my regular environment and I can **not** reproduce this bug in 5.27.80. So there is a high chance this bug is fixed in 5.27 and hopefully will be mitigated once my machine updates to 5.27 in a few days.
Although, I want to point out that I noticed the primary display, in 5.27, will however blink once (not instant blink, more like a fast dimming animation then back to normal) before going back to normal.
*** This bug has been marked as a duplicate of bug 450068 ***