How to delete video files on iPad, that are listed as "from my mac"

Hi experts,

I have two video files, combined size around 8 gb that i no longer need. I cant, however, seem to be able to delete them. In my photos app, they are listed as "from my mac" (in danish "Fra min mac"). I dont own a mac and i have no idea why they are listed as such. Its been 3 or so years since i put them there. I can select them, but the delete button is greyed out.

They may have been imported through dropbox, via the app Lumafusion, but i have since deleted Lumafusion, so its not because the files are in use by this app.

Its a Ipad pro 2nd generation, 12,9", 512 gb without simcard. I run IpadOS 16.3.1.

Its a slight issue, but its been bothering me for some time, so i hope someone can help me.