I have been using NoMachine for almost 5 years using a 2017 intel iMac as a server machine without this issue. I recently upgraded to a M4 MacMini and this has been bugging me a lot. My client machine hasn’t changed.
The issue is that the partial refresh of the screen is of a slightly different color than the rest of the screen. This causes mild flashing of the screen and is quite distracting. I have tried different quality settings, all available display encoding, and a lot of different settings. I don’t have access to my previous server machine anymore, but I triple-checked all my settings to make sure they were the same on both server machines. I even tried to reproduce the issue on the intel imac without success.
Server and client machines are currently using NoMachine 8.16.1. Server machine is using MacOs 15.3.1.
I have attached a screen recording of the issue. It is recorded from the client machine, since it is not noticeable if i record this from the server. I have also attached a log of my current session.