After switching to Plex Pass PMS is constantly utilizing one core (version 1.14.1.5488)

[sa2000]

The issue with high CPU when uPnP enabled has been addressed in Plex Media Server 1.16.2.1297 which has just been beta released

See release notes

Plex Media Server

Plex Media Server 1.16.2.1297 is now available to Plex Pass users in the Beta update channel NEW: (Web) Updated to 3.99.2 FIXES: (Add to Library) Hi-fi quality was limited if TIDAL account was not managed through plex.tv (#10155) (Localization) Translated strings were not returned (#10168) (NAS) Ensure transcoder temp directory is present at startup on Synology devices (#10213) (NAS) The server might not automatically start after system reboot on Synology devices (#10236) Greatly speed up …

• The server could use large amounts of CPU when running on a network with certain routers with UPnP enabled (#9610)