Plex media server platform (Win/Linux/etc)?
It appears you are running PMS v1.19.2.2737, released in April 2020.
If possible, update to a the current release, 1.23.4.4805 or 1.23.5.4801 (Plex Pass / beta).
Others running older versions of PMS have reported the same problem. Updating to a current PMS release has fixed the problem for many.
