Finally writing to list, to have it easier to come back to debugging
steps.
First, environment. Laptop (Dell Latitude 7490, i7 8650U, integrated
graphics card), thunderbolt docking station. Two external monitors, DP
2560x1440 above laptop screen, DP->DVI 1920x1080 rotated to the left.
Using i3, with workrave and redshift running in dom0.
Now, the issue.
Every so often, when starting VMs, screen flickers like i3 was maybe
restarting, and all the icons in system tray that come from VMs
disappear. Sometimes the system tray will completely cease to exist, I
don't remember whether the i3bar is displayed then or not, might not
be.
Where should I look what's happening, how to try to debug this?
Thank you in advance for hints!