The behaviour where you press a menubar item, drag down to a menu item, and release to trigger it is absent.
*** Bug 447261 has been marked as a duplicate of this bug. ***
*** Bug 453590 has been marked as a duplicate of this bug. ***
Upstream bug report: https://bugreports.qt.io/browse/QTBUG-107994
Ah thanks. Makes sense that it can't be done by us here.
*** Bug 483575 has been marked as a duplicate of this bug. ***
*** Bug 487162 has been marked as a duplicate of this bug. ***