USB keyboard not recognized at XFCE login


I have configured my USB device to be contained in a separate USB qube:

sudo qubesctl state.sls qvm.usb-keyboard

This works so far, but from time to time I get stick in the XFCE login menu!
Today I needed two further reboots until keyboard became available for input to enter credentials.

Unfortunately, I don’ know to debug this problem. Some hints:

  • At boot time, LUKS password can be always entered successfully via keyboard (USB devices active)
  • Then, with XFCE display manager / login menu, either two situations happen:
    • all USB devices are turned off and keep inactive
    • all USB devices are turned off and toggled on again (they seem to do this twice, I suppose to clean USB stack for security?)
  • Problem seems t o happen arbitrarily due to race conditions at boot - I experimented with waiting some time at LUKS encryption input, but could not make out a rule
  • There haven’t been any USB instability / hardware issues with different OS

Is this a known problem and does an github issue exist?

Thank you very much for having created an awesome OS!