So frustrating

I have been dealing with this weird thing with Rush. I am on an iPhone 11 and shoot 4K. When I take the videos, they're fine. However, when I put them into Rush, a couple parts of a few videos will become pixilated for a split second. Never longer than 2 seconds or so, but it's enough to render the clip useless. I don't know how to fix it, what I'm doing wrong to cause this, and it's ultra frustrating. Sometimes it will freeze, and I can't do anything besides exit the app. Other times it will open but the audio won't play, nothings muted and my device audio is up. Plus, today the app just crashes mid-edit and all my work is gone. I don't know how an app from Adobe can be stood by--by Adobe--with these blatant and annoying flaws. I am a paid subscriber too which is all the more frustrating.