Seemingly random clips refuse to be added to the timeline

Hello! I'm currently in the editing process of making a short film using Premiere Rush on my iPad. I've been storing clips on the Apple Photos app, and everything has been going smoothly so far except that I've found that some clips refuse to be added to the project. Nothing appears to be wrong with them, they play well in the Photos app and even play well in the preview screen before tapping the "add" icon. Everything has been recorded on the same camera, and the clips that don't work all come from different sessions. The only other thing I can think of is some of the broken clips use a higher resolution, but then again some of them don't and some of my other clips of the same higher resolution work perfectly. It's also not an issue with the project itself, I've tried creating a brand new project from scratch only using these broken clips and they still won't appear on the timeline. I could do reshoots, but I don't want to go through the hassle if there's a reasonable solution to this weird issue. I hope what I've provided narrows it down, but I can give more info if necessary. Thanks!