Plex Not Downloading Album Covers

I just don’t understand why it’s not downloading. It did it before and it seems to have kept a few (like 10), but the majority of albums it’s not downloading. When I refresh the library it downloads all metadata, but not album covers. I’ve read this:

https://support.plex.tv/hc/en-us/articles/201424327-Why-do-I-get-metadata-but-no-images-for-my-library-items-

so many times.

How can I troubleshoot this?

I should add that I run Plex on Ubuntu GNU/Linux with an ext4 filesystem

To troubleshoot, enable debug logging on the server, shut down the server, purge the contents of the plex media server logs folder and also the logs in pms plugin logs
Restart the server
Create a test library - TV shows or movies category with media named and structured as per the gaming convention specified on the support page
At the end if the scans, have a look at the server logs /- of interest will be the agents logs in the PMS Plugin Logs which should show the matching of your media files to tv show or movie and the download of images

See
https://support.plex.tv/hc/en-us/articles/201643703-Reporting-issues-with-Plex-Media-Server
https://support.plex.tv/hc/en-us/articles/200250417
https://support.plex.tv/hc/en-us/categories/200028098-Media-Preparation