Not to add ambiguity, but i'm dealing with a similar issue with ESR where if even the laptop display turns off for an extended period of time, on wake, the CPU usage spikes and I have to SIGTERM/15 Firefox to get it to recover. I was debating migrating from ESR to latest, however I also suspect there could be something system wide going on as Signal desktop is also having an issue refreshing after wake as well. The thing that's baffling me is that I supposedly have all power management (while plugged-in) disabled so I'm not sure what's going on. This is on a stable Kali Purple build with default XFCE DE, i5 and 16GB.