Has anyone downgraded to Ventura to try and resolve? Does that fix it?

Came back to say my laptop is 100% fixed with no screen issues at all. Saved me so much money!! Thank you @richardh9935 Solution is to delete all the duplicate colour profiles from ~/Library/ColorSync/Profiles/

I also have this issue - I was on Ventura when it started, after a few years of using an LG external monitor with my MBP M1 early 2020. I upgraded to Sonomo 14.1.1 and it's drastically reduced, but still flickering very occasionally. I have just tried the advice above - to delete duplicate colour profiles (I had a lot of LG duplicates and also Color LCD duplicates). Will report back if it works! I really hope so as I also took it to the Apple store and they said it needs a new screen for £600. Doesn't make any sense as it's a well looked after machine.