This is the video I was talking about- the CPU cooler being the cause, even though temp it shows were fine.
The problem is I do not have all the other items to test each component by replacing them and testing with new components.
So sending them to a repair shop seems to be the best option which is not valid right now due to covid restrictions. It is really frustrating.
edit: 4 reboots today, while just writing on this site using google chrome. So there was no stress on GPU and cpu.