It sounds like a hardware issue to me. As soon as pressing/hitting on the case of a computer fixes something, it is probably some dust or a loose contact or another hardware failure. If you still have your notebook under warranty, I would record a video about what's wrong (so you would not have to "reproduce" it when you are there), and send it for repair. If you need to send it via mail, upload that video before contacting the service and send them the link. I do not believe updating drivers or reinstalling OS will solve anything.
One thing though. For the sake of experiment, try going to BIOS (probably F2 during boot) and just stay there for a couple of hours and try to move the notebook to another location and try pressing keyboard keys that trigger the problem. this way you will verify that this is not the driver/os problem.
