SUMMARY I am not sure that this bug is related to the kwayland-integration, but it is using wayland (my best estimate) I have dual 4K monitors (3840x2160@60hz), running in extended desktop (landscape side-by-side) with both monitors at 110% scale. When playing a YouTube video in firefox, it behaves normally until the video is put into fullscreen mode (does not matter which monitor), the other monitor starts to misbehave. This does not occur for other applications such a VLC. STEPS TO REPRODUCE 1. Open Firefox 2. Play a YouTube video 3. Put video into fullscreen mode 4. Move mouse onto other monitor OBSERVED RESULT Windows on second monitor disappear (become hidden) while the mouse is moved on that that monitor and reappear when the mouse is pulled back to the original monitor. EXPECTED RESULT Windows on the second monitor remain visible and usable while YouTube is playing in fullscreen on the first monitor. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Operating System: Fedora Linux 40 Kernel Version: 6.11.3-200.fc40.x86_64 (64-bit) KDE Plasma Version: 6.2.1 KDE Frameworks Version: 6.7.0 Qt Version: 6.7.2 Graphics Platform: Wayland Browser: Firefox 131.0.3 (64-bit) ADDITIONAL INFORMATION Worked without issue on plasma 6.1, and timing seems to coincide with the plasma 6.2 upgrade.
After exiting YouTube fullscreen, if I go into the Display Configuration and disable the affected monitor, apply the changes, then re-enabling the monitor again; then I can avoid rebooting the computer. Rebooting will also remediate the display issue. Turning the monitors off/on or removing the HDMI cables has no affect
Hi Chris, I might have had the same bug and had opened a bug with no success with Firefox. Is the behaviour similar to mine? https://bug1925340.bmoattachments.org/attachment.cgi?id=9431651 Also a workaround you could try is starting firefox with `MOZ_ENABLE_WAYLAND=0`. This will change the window protocol from wayland to xwayland and was how I could keep using firefox since the Plasma or Firefox update introduced the issue. I could also reproduce the issue with a fresh secondary account and was recreating my desktop layout until I found that setting the fractional scaling values for the screen seemed to the culprit. For me one screen is 120% and the misbehaving one is 110%. In trying to see if I could flip which screen goes bad I messed around with the values and this seems to have fixed my problem. So maybe a more permanent fix could be messing with the scaling values again and see if this magically clears whatever caused the issue.
Bogdan (In reply to Bogdan Dragoiu from comment #2) > I might have had the same bug and had opened a bug with no success with > Firefox. Is the behaviour similar to mine? > https://bug1925340.bmoattachments.org/attachment.cgi?id=9431651 Yes, this does look like the same behaviour > Also a workaround you could try is starting firefox with > `MOZ_ENABLE_WAYLAND=0`. This will change the window protocol from wayland to > xwayland and was how I could keep using firefox since the Plasma or Firefox > update introduced the issue. I just tried starting with MOZ_ENABLE_WAYLAND=0 firefox MOZ_ENABLE_WAYLAND=1 firefox and both of these behaved correctly, so then I went an tried firefox from the icon and it also worked correctly for a while and then the second monitor bugged out after a few minutes, so it looks like a can't reproduce this 100% of the time anymore. The only new change is Yesterday, firefox updated to 132.0. The release notes for firefox 132.0 https://www.mozilla.org/en-US/firefox/132.0/releasenotes/?utm_source=firefox-browser&utm_medium=firefox-desktop&utm_campaign=about-dialog do not mention anything specific to wayland, and the closest change that may have some effect is "The getCapabilities method allows applications to gather the media capabilities supported for the live MediaStreamTrack." > I could also reproduce the issue with a fresh secondary account and was > recreating my desktop layout until I found that setting the fractional > scaling values for the screen seemed to the culprit. For me one screen is > 120% and the misbehaving one is 110%. In trying to see if I could flip which > screen goes bad I messed around with the values and this seems to have fixed > my problem. The 110% we have in common > So maybe a more permanent fix could be messing with the scaling values again > and see if this magically clears whatever caused the issue.
After futher extended testing, I can still reproduce the problem via starting firefox from the icon or with command line: > MOZ_ENABLE_WAYLAND=1 firefox However starting with command line: > MOZ_ENABLE_WAYLAND=0 firefox is preventing the issue from occurring over the extended time While this can be bypassed in this manner, it is not a convenient way to start the app