Macbook air M1 external screen flickering

I have a Macbook Air with M1 chip (2020, Ventura Version 13.4.1).

I've tried connecting it to an external monitor but I get a LOT of flickering (only on the external monitor). sometimes parts of the screen flicker and sometimes the whole screen turns black for a couple of seconds.

Since then I have switched all of my cables and tried another monitor - It didn't work.

The 2 monitors I have are old, I am willing to buy a new one but I'm not sure which one will work (I'm not strong in the monitor market).

I usually use my monitor for coding, not gaming, so I don't need anything fancy.

Any tips on how to solve this issue will be appreciated as well as a cheap monitor recommendation that will work with my Mac.

My 2 old monitors:

HP 20" W2007

Fujitsu L22T-2

Thanks for the help :)

Update: I received a suggestion that I should change the Refresh Rate in my external monitor, but I only have 60 Hertz in the drop-down menu.