This problem occurs on macOS platforms when the NoMachine session is sent to fullscreen. The Apple menu covers the session as if it were not truly at fullscreen. 

This issue is caused by the underlying framework on which the NoMachine application is built and can only be fixed by updating that framework, something which we have already planned in our development roadmap, and for which an internal feature request is already open (we do not make our roadmap public). Work is ongoing.

This TR has been opened to allow macOS users to track the issue and its eventual solution.