Macbook pro 2018 with Ventura 13.4 and Dell U4021QW is unusable

Today I bought a second hand MacBook Pro 2018 (intel) with Ventura 13.4 installed and it appears to be working fine, until I plug the external monitor.

When I do that, both the laptop monitor and the Dell show glitches which seem to be software related and not cable or issue with the laptop. For example the mouse cursor is displaying normally on top of the glitches or when I rebooted to reinstall Ventura, both monitors were showing correctly.

Things I have tried so far:

Works fine

-4k TVs using usb-c to hdmi adaptor & hdmi cable- Works fine 

Same result

-USB-C to USB-C cable that came with the monitor and I’m also using to run other laptops to the screen

-USB-C to display port adaptor & display port cable

-USB-C to HDMI adaptor & HDMI cable

-I tried reinstalling Ventura & reset all the settings

Findings

-The monitor itself is fine

-The laptop itself is fine

-The cables and adapters are fine

-Reinstalled latest version of Monterey and the issue was not there anymore.