Random xorg in qubes takes a bunch of CPU

I’ve found that intermittently my CPU starts going crazy and idles at 50%. It is seemingly a random qube that I’m not using that is hogging the CPU, when I open a terminal in that qube it tends to immediately stop hogging the CPU so I can’t see what process does this except for one time where I was quick enough and it seemed like xorg was one of two culprits (I wasn’t quick enough to see the other). What could be making xorg take up 25%-50% of the CPU in an idling qube that has no window open?

Just found out the other process is at-spi2-register

You’re not alone - I’ve been encountering this issue for a loooong time on my laptop (T450s). It happens quite rarely, after closing the last window of a qube. It looks totally random, I could never find a chain of events that would reproduce it. It seemed to happen mostly with sys-usb.
FWIW I’ve been using a desktop PC for the past few weeks and I’ve not encountered the issue.