Primary Image Metadata

[Macaroni]

Id say around 5 percent of the movies in my libary default thier primary image to this collage of random screens from the movie      . I have wil then manually change the image but after a short amount of time it just changes back. I have tried changing the metadata souces and resetting the libary metadata but nothing has solved my issue. 
Any help woud be apreciated! 
Thanks

[ArneR]

That's probably because that image file is located in the same folder as the movie. Simply delete it or rename it with a "." before the filename, and jellyfin no longer sees it.