Figured it out… turns out it was more of an Open Media Vault issue than anything else. OMV mounts external partitions as noexec by default, and since my library, temp files, etc., are all on a mounted partition that is not the OS partition, this seems to have caused a bunch of issues with plex not having enough privileges to run “normally”.
removing the noexec fix is described here Filesystem Environmental Variables — openmediavault 5.x.y documentation
rebooted OMV, restarted Docker, Portainer, and the Plex container, and everything is trans-coding fine now, no more errors.
Got the inspiration from those posts :
and
Hope it helps!
