In one of my VMs, I regularly see that hp-systray is running at 90% or so. Killing hp-systray solves the immediate problem, until the next time hp-systray decides to run out of control.
Qubes release 4.2.3 (R4.2)
The vm is based upon debian-12
The worst of the vms is the one I used for running firefox, which has too many tabs open. Some day, I will clean them out faster than I create now tabs.
Perhaps the run-away hp-systray is caused when firefox runs out of memory, causing firefox to crash, and putting hp-systray in a bad state.
But I am not yet sure that hp-systray problems are limited to firefox memory issues.
clone the template, run hp-systray in it without firefox, use firefox in the original qube, see if hp-systrays has the same issue