Honesty... it took a screen change and a motherboard change to fix it. Never pinned it down to whether it was the screen or motherboard but pretty sure it was the mothwrboars. Dell replaced it under warranty. I had two screen changes.. on the second screen change the technician shorted my laptop out and blew the motherboard. After the replacement was installed the problem never came back.
It's very annoying but I tried all the gpu updates and process kills before looking at the hardware and nothing worked permanently.
Defo a hardware failure.