Server Version#: 4.111.1
Player Version#: 8.21 (6341)
tvOS software version: 16.5 (20L563)
Displaying Personal Media libraries in grid view seems to show overly low resolution images for the custom cover-#.jpg files I’ve made for the videos. I deleted the Plex app from the AppleTV to reload, and I deleted the transcoded photo files directory from the server to force recreation of the media.
This seems to occur regardless of whether the custom file is titled cover-#.jpg or poster-#.jpg.
Custom background-#.jpg are displaying at sufficient resolution when they are required.
Custom covers display with adequate resolution on web client. It’s more difficult to tell with the smaller images on iPhone client, but these also appear to be lower resolution.
Looking at the recent server logs, there are a number of requests to create thumbnails at 240x135 pixel resolution, I speculate that these are the files being supplied to the AppleTV and iPhone clients.