We are having the same problem, but only for buttons that do not have an action attached to them. So instead of commenting out code in the component, we implemented a little hack: (force the dodropdown)
THackRZButton = class(TRZToolButton)
public
Procedure DoDropDown; override;
end;
procedure THackRZButton.DoDropDown;
begin
inherited DoDropDown;
end;
Then add the onclick event (not an action) to the button itself and call the hack to force the dropdown:
THackRzButton(Sender).DoDropDown;
This works for us, gives the same results as the original TToolbar we are replacing because it doesn’t work correctly under High-DPI.