I'm just about to log a call with Sony.
I shoot weddings and events. So far, three uses since it has arrived, all shooting 4K 25fps 4-2-0 60mbps the camera overheats and stops at a little over 30 mins each time, in winter in the UK during ceremonies and speeches. Twice on a tripod with screen out, once in hands. The camera to touch feels very very hot. My a7iii cameras just keep running and running. So there is certainly an issue OR maybe some dodgy units. Maybe the sensitivity option you can set in the menu is not working? I've a friend who isn't having issues at all. Sony SD card and Sony batteries.