Legion pro 7i 5090

Hi, had my laptop for a month or two now. A while back it started going black screen for a few seconds sporadically on external monitor, sometimes within a couple minutes sometimes fine for upto an hour.

I’ve realised it does also do it when only using the laptop screen, occasionally it also flicks to 60hz, goes off again and comes back one at 240hz?

I’ve turned off hybrid gpu, dynamic refresh in both windows and legion space, updated drivers..

Anyone got any ideas? I don’t know if the laptops faulty or it’s software?