I have a TV Show called "Sonny Boy" that I added as a Streamlink the other day. It is a brand new show and when I went to add it the image was the generic TV. I came back a few days later and confirmed it has an image now:
So I did the "Refresh Show Description", but the image did not change:
The individual episode changed, though, just not the TV Show:
I also tried just fixing as an incorrect match; changing to another program and changing it back; and removing it completely / pruning / re-adding to no change. I am on pre-release version 2021.07.21.0855.