Green flecks on 8 inch screen

I have just built an 8 inch Picade with a pi4.

All working fine, however on the screen there are what can only be described as green flecks that move around the image. On some things there are also red ones. It’s very odd.

I tried to upload a pic but cannot as a new user. I’m just wondering if there is a setting I need to adjust or if the panel itself is faulty.

UPDATE: The monitor was faulty. Replaced and sorted.