I have the same problem when using the latest versions of NoMachine. However, when using the client of NoMachine 4.0.346_1, the resolution of the host is maintained by using “keep original aspect” in the settings on the client side. I tried all types of setting combinations in the client of the two latest versions, but could never get it to perform as well as the version I’ve named here. My host does have the latest version of the software. It’s only the client that needs to use the earlier one.