Images uploading for cast credits

This is under the individual episodes for television credits, when you go into images, under the episodes. 

You click on the uploader to select a headshot file for an actor credit, no worries. Yet recently each attempt gives me a file warning of 5000 x 3000 size, which is incorrect, as I've previously uploaded thumbnails without any issues.  What happened?   

No matter what I do, the loader will not budge from the 5000 x 3000 size, which normally refers to like a full studio or production shot. While headshots are typically smaller thumbnails.  I wish to get this finalized with the appropriate headshots on my episodes please.

Thanks for the help!