I can report that I have now been online for 1 day and 20 hours with no crashes since I removed the device /dev/dri from the Plex container.  If it remains stable for a few more days, I may re-add the device and pin the Plex container to the efficiency cores of the CPU. It's possible threads moving across different types of cores is what causes the crash, but this is pure speculation on my part so I'll have to test it out.   Thanks for this tip! I actually worked late last night s