Flashing keyboard and screen, crashed sys-usb after unlocking my computer

Hi Community, sorry if my post’s description is poor quality, I try to describe my problem here as clear as I can.

After was I unlocking my computer, the Qubes Manager was not responsive. Waiting less than a minute, the screen started flashing, basically turning on and off every second. After a few flash, the keyboard light of the alt button started to flashing as well, very bright. It lighted up in sync with the the screen’s flashing, every moment the screen become dark.

Suddenly the flashing stopped and the Qube Manager was responsive again.
Here I recognized an odd thing: the sys-usb’s state was suspended.
I tried to restart it, but it become unresponsive again. I killed and restarted it.
It’s state stayed “Transient” (yellow) for a long time, and after I got the following error message from dom0:

Error Starting Qube!

Start failed: internal error: libxenlight failed to create new domain, see /var/log/libvirt/libxl/libxl-driver.log for details.

First libvirt gave a permission denied message, in root I reached the log file, but not sure which application can I read it.

It is hard to imagine and seems unlikely that someone gained physical access to my computer, as I was just in an other room when my computer was locked. But of course, who knows.

If anyone can help, thank you!!