I’m actually having similar issues. Seemingly at random, my PC will freeze up due to lack of memory and killing Firefox fixes it. Im also sure it must be an extension causing it.
Here are my extensions, let me know which of these you are using and maybe we can narrow it down from that:
- Neat URL
- uBlock Origin
- Return YouTube Dislikes
- Firefox Multi-Account Containers
- SponsorBlock
- Vimium
- Decentraleyes
- Enhancer for YouTube
- Privacy Possum
- I don’t care about cookies
- First Party Isolation
- Startpage Privacy Protection
FWIW, the only ones we share on that list are uBlock, Dislikes and Enhancer.
Again, best guess is Youtube is desperately trying to poop out some ads and getting reinvented within an inch of its life by those extensions (not to mention dragged kicking and screaming into having pop-up playback windows) and something breaks in there somewhere. I’m not holding my breath for a fix anytime soon.