If they aren’t showing in the Purchased section for redownloading , and if they are still in the store and if you haven’t moved countries since buying them, check to see if you’ve hidden them : Hide and unhide apps for your iPhone, iPad, iPod touch, or Mac - Apple Support
If they aren’t hidden copy them from your phone to your computer’s iTujnes library and sync them
This was ridiculous because those same videos....were still on my iPhone!
? Items can still be stored on a different device, not being downloaded or available to download on one doesn’t automatically delete it everwhere.