macOS: Qt doesn't respond to key combinations read by VoiceOver

When VoiceOver is enabled, it will read out what is selected on the screen, and how to interact with it. It also shows this as text in a window. See attached screenshot. The focussed/selected item in that screenshot is of a button with a menu.

This issue is:

• pressing the mentioned Control-Option-Space does nothing
• pressing space will select it, but this is not obvious.

This problem shows up in a number of places: when using the tab-key to focus on a list view, the mentioned/hinted key combinations to interact with the list do nothing, but arrow navigation works (but is never mentioned).

To reproduce: run any example application with VoiceOver turned on, and use the tab/arrow keys to navigate. Then try to use the spoken/shown key combinations to interact with the focussed widget.