So with my experience I've found using a go pro hero 7 that you cannot cut clips in go pro app then export to iPhone camera roll and import to rush.. clips will not let you render & kick you out.
secondly when you try and render a lot of times it stops and kick you out like a program fail.. I have to watch which clip it was on then go back in and delete that clip and bring it back in to redo because for some reason it doesn't like something.. maybe a screen zoom change or a split screen view .. I have no Idea but it's driving me nuts..
I use a go pro hero 7 for video, then bring full clip into iPhone 8 camera roll then import to adobe rush to edit.. then render.. my iPhone has lots of availability for storage 20G free, full battery, only a 10min video..
those are my issues.. how do I stop this from happening all the time?