to GoPro support, this is a software / firmware bug and can be replicated on many GoPro's as below. I actually already sent in a GoPro and it was replaced with a new one, that has the exact issue.
Again, it happens approximatel 1 in 10 clips.
Please investigate.. If I call GoPro they just go through the regular troubleshooting questions etc.
So I called support yesterday about the issue. The first thing she tried to tell me was that 4k/30/Superview was not supported with Hypersmooth and that is why I was having the issue, she even sent me this link https://gopro.com/help/articles/block/what-is-hypersmooth
I pointed out that it clearly shows it is supported, she still insisted that it wasn't and made me send her a picture of the camera showing it was enabled, so I sent her the picture below. She then told me to only use 1440p/30/wide and see how it works. I said no I need 4k/30/superview as advertise. I was then told they never have problems with Hypersmooth so I need to RMA it and she set up a return. No once did she admit that it was supported and she was wrong.