Fedora-41 AppVMs not updated for monitor layout change / external monitors which leads to unclickable areas

Hi,

when i connect an external monitor, fedora-41 based AppVMs do not recognize the new clickable area and thus have to be restarted to be working again. In debian-based AppVMs, this is working flawlessly.

This is not related to video ram adjustments as discussed at GUI configuration | Qubes OS

I’ve tried my best to debug the issue:

When I connect the new monitor, debian-based VMs have the following xrandr output and are working fine:

Screen 0: minimum 64 x 64, current 3440 x 2640, maximum 32767 x 32767
DUMMY0 connected 1920x1200+0+1440 325mm x 203mm
   QB3440x2640   18.90 +
   QB1920x1200   59.88* 
DUMMY1 connected 3440x1440+0+0 0mm x 0mm
   QB3440x2640   18.90 +
   QB3440x1440   59.94* 

In contrast, fedora-41 based AppVMs have the following xrandr output and the area within the “old” resolution of the original monitor (1920x1200) is clickable but the extended one (3440x1440) is not:

Screen 0: minimum 64 x 64, current 1920 x 1200, maximum 32767 x 32767
DUMMY0 connected primary 1920x1200+0+0 325mm x 203mm
   QB1920x1200   41.50*+
DUMMY1 disconnected
   QB3440x1440   59.94  

Now, when I reboot the fedora-41 based AppVM, everything works fine and the xrandr output is correct and I can click everything. The same works if I do systemctl restart qubes-gui-agent in the fedora-41 AppVM and without a restart, all windows disappear but then the xrandr configuration is correct and I can restart apps in the still running AppVM and click everything.

Interestingly, when I run qvm-start-gui --notify-monitor-layout AppVM in dom0 I get the following errors in journalctl output of the AppVM:

Jan 04 18:53:49 AppVM qubes.SetMonitorLayout-dom0[3675]: X Error of failed request:  BadMatch (invalid parameter attributes)
Jan 04 18:53:49 AppVM qubes.SetMonitorLayout-dom0[3675]:   Major opcode of failed request:  140 (RANDR)
Jan 04 18:53:49 AppVM qubes.SetMonitorLayout-dom0[3675]:   Minor opcode of failed request:  7 (RRSetScreenSize)
Jan 04 18:53:49 AppVM qubes.SetMonitorLayout-dom0[3675]:   Serial number of failed request:  186
Jan 04 18:53:49 AppVM qubes.SetMonitorLayout-dom0[3675]:   Current serial number in output stream:  187
Jan 04 18:53:49 AppVM systemd[728]: Started dbus-:1.2-org.xfce.Xfconf@3.service.

For me, this looks similar to the issue mentioned in monitor layout change regression in 4.0-rc2 · Issue #3253 · QubesOS/qubes-issues · GitHub but I’m not quite sure. Any hints or suggestions?

Thank you
David