Like all the other GH5/GH5s owners im having the same issue with the Focus wheel stop working blink red, loosing control of focus and record/stop. I decided to take off the focus wheel off to see if I could still record and it does work.
You can still half push the record button to focus start/stop record you just cant pull focus but seeing how the focus wheel is not the greates I only use the half push of the record button. I did this for about 30 min and never lost the fuction of the record/stop or hlaf push ot focus. Hope this helps some of you until DJI comes out with a firmware fix.
Still need a work around on using my Ninja V and the black screen.

Good to know thanks for sharing this. Since this thread is a few months old, do you know if this has been fixed with a firmware update? I'm researching the Ronin S for use with a GH5, haven't actually bought it, and your experience is super useful, so thanks.