I'm having the issue with shows, and assumed it also applied to movies. But it turns out the only virtual channel I checked was the one where I didn't include custom images for movies! So after double checking, movies DO show my custom images if I have included them.
However, I'm definitely having the problem with shows. For example, I have a Doctor Who virtual channel with seasons 1-9 of the 2005 iteration of the show. I have a single custom image for the overall series, and then custom images for each individual episode. When I view the show through my library on my Apple TV, all these images appear as expected. But when I go to the virtual channel and scroll through the episodes in the guide, they all use an an image from the most recent season of Doctor Who (season 13) that I did not select.
This is true of all the TV shows in my virtual channels where I uploaded an image for the show. They instead seem to use one of the first images from the internet image picker.
Another hint of what might be causing the problem: Using the Web UI, if I select a show from the Library tab, it shows my images. If I select the same show from the DVR tab, it shows the image the virtual channel uses that I didn't choose. Weird.
Thanks for any insight. I assume I'm doing something wrong since I don't see anyone else talking about this issue!