Whenever I include an action button in a group and set that group visibility condition I get a bug in which the action button is still visible. The action buttons still obey their own visibility conditions but they do not seem to obey the group visibility conditions.
Here’s a cloneable example of the bug in action Button grouping test (text is invisible, normal button is invisible, floating action button is visible)
It doesn’t work because the group has style Fixed = None (see Edit Styles on the left bottom). Action button has another built-in style (as I think Fixed = Top).
Visibility seem to be evaluated separately for the styles.
Try to change the style for the group and see if it works for you.