Issue has been solved via this post: Some plex apps now giving error: “An error occurred while attempting to play this video. Please check your connection and try again.”
Within that post, downloading PLEX 1.23.X, and then performing a “Manual Install” within Package Center on my Synology, also fixed my issue. Interesting how it doesn’t auto update to the most current version of PLEX for the Synology NAS.
