Oh weird 🤔 I've never properly used primal so can't say. But on amethyst you can select which img host you use. I use nostrbuild. And I think it doesn't have any problems with image uploads. Also fine with video (up to a certain length). It does reduce quality of video. But does this all for you.

For longer video I've found this (let me find it) free file hosting site (no associated at all with nostr, but useful)....