Auto upload only works with pictures and videos? Not for other file types?

I have just setup my nextcloud server, and on the Android client app, I used the function auto upload and setup custom folder to auto upload some pdf and signal backup. However, non of that worked. It will only upload pictures from other auto upload folder. I tried moving the pdf.files to the picture folders that work, but still no luck. Is auto upload limited to picture and video file types?

I have the same issue with my music library. It would be cool to just have a checkmark wether you only want media or all file types to be uploaded