Unable to add video or gifs to Product Previews using Firefox

It seems a lot of my products have an issue where when I attempt to add a video or gif file to the product previews/thumbnails section, the site will show the file uploading, but when the upload completes, the video/gif will not show up in the intended section, either when editing the product entry or on the actual store page for said product.

This is occurring when I'm uploading via Firefox, with some adblockers/privacy plugins active; when I use Microsoft Edge to do the same action the upload works correctly, so I can only assume Firefox itself is interfering with video/gif uploads somehow. I experimentally turned off some of my adblock/privacy plugins to see if that corrected the issue, but no change, the bug still occurs.