keyboard.AltKey test fail

The LR says:

If True, the Alt key on Windows and Linux and Option key on Macintosh was depressed when the current method or event handler began.

Nice, this is exactly what I wanted to know / to do but…

The example from the LR:

If keyboard.AltKey Then MsgBox "Option/Alt key" End If

fails miserably under Linux Mint 18.2.

Nota: .ShiftKey works fine.

Nota (bis): I have troubles with the PCAltKey as found in MenuItems and so I avoid to use that. For other reasons, I started to use to test .ShiftKey and that worked fine.
I wanted to remove that mind blockage and so I started to test that (under VirtualBox).