@Dr_Midnight
For all systems, Fedora 26 / Ubuntu 18 and above, plexmediaserver.service is obsolete.
The systemd standard, as published for systemd, is /etc/systemd/system/app_name.service.d/override.conf
as documented here (2018)
I’ve not had any luck reproducing this --YET–
Yesterday, I started a full rebuild of my one server. When it finishes, I’ll see what the status is.