Power disconnects randomly from plug/extension lead

I have a plug socket in my bedroom connected to an extension lead which connects to my monitor and my pc (through a surge protector) and a clock. It used to be connected to my PlayStation and TV but that's not the case anymore.

Semi frequently, it will lose power and everything will be switched off. I was convinced someone was coming in and doing it because I had never been home when it happened but I checked the logs on my pc and nobody was home when it happened.

Idk what could be causing it but its super annoying and my pc was running a program for like 20 hours that should have been finished by now but has had to restart. Any help/insight would be super great, thank you.