Just to check on your home piefed instance try uploading a immage from web in a comment (or post body) not as post.
If the web ui gives u a markown for uploading images instead of usual select image then might be piefed issue.
I could be wrong though i have been using pifed for a day only.
I kinda want to ask how well does firefox work? I kinda want to try using amazon prime one firefox with ublock origen (yes I know jelly fin and plex plus other tools exist) just curious