Package: x2goclient Version: 4.1.1.1
When connecting to an X2Go server (version 4.1.0.0-0~1517~ubuntu12.04.1; arch x86_64, with nxagent version 2:3.5.99.16-0~201803162252~ubuntu12.04.1) using X2Go client (version 4.1.1.1-0~1719~ubuntu16.04.1; arch x86_64), in fullscreen mode, the keyboard shortcut Ctrl-Alt-M does not only minimize the client window, but it is also echoed into the application currently running on the server (as if it was pressed locally on that machine).
I would expect the Ctrl-Alt-M shortcut key to be swallowed by the client, so that it does not reach the server.