I run Plex and Emby side by side. I posted below in Plex forums as both emby and Plex are having the same issues.
"Do you have any idea into what might have happened? My server hasn't undergone any changes, and this issue with the posters being stitched screencaps from the movie has never happened before, but suddenly it's occurring."
See file attached.
Now on Plex forums, I was advised to turn off, uncheck the following
Use local assets
When scanning this library, us