Okay here’s a weird one. I’m not sure if it’s related to the PMS build or if the Plex app on Xbox is having a bit of a freak out with the libraries, but all of a sudden the wrong backgrounds are being used for the Entertainment screensaver. It seems like every second title uses the incorrect background image. Just now they were using Gummi Bears, now they’re using Unikitty!
My initial thought here is that the server has no background artwork for these titles and so falls back on the last shown artwork with the closest title match (going as far back as simply matching the first letter).
I rebuilt my library from scratch two days using entirely the new agents/scanners (I don’t like to do things in half measures 
) so not sure if things like background artwork for the screensaver only get pulled during maintenance?
The same (or very similar) thing has been happening on displaying the libraries in the Home section. Each library’s “Recently Added” shows the same poster sequence. I’ll try get screenshots of that when I can. It was happening before I nuked my PMS folder, i.e. when I was still using the old agent/scanner but had a separate library with the new one too.
