If "Grab the keyboard input" is checked in settings of NoMachine Player for Windows, the Win+key combination are not sent to the local Windows desktop but forwarded to the remote desktop which the Player is connected to. For example, Win+V is used to paste text in a remote macOS desktop (Win key emulates the Apple key).

Sometimes the Win key is not forwarded, but captured by the local Windows desktop (in that case, Win+V launches the Clipboard Tool on Windows 10). After that the Win key looks stuck for the local Windows desktop: any further pressure of "V" key would display the Clipboard tool aw "Win+V" were pressed.

To fix the stuck key: move focus away from the Player window, press and release Win key to display/hide the Windows menu, then give focus to Player window. Wait two or three seconds before pressing Win+key combination.

Note that the problem occurs each time the Win+key combination is issued just after the Player windows get the focus within a short time (less than one second).