What is xtpButtonAutomatic for?

I have added several xtpControlButton CommandBarControls. I would like for them to at like a group of option buttons on a frame, where, when one is selected it becomes checked. If another of the buttons is selected the previous button becomes unchecked and the newly selected button becomes checked. This happens automatically when using option buttons on a frame. However, it doesn't appear to work that way, at least for me, using the CommandBarButtons which are all children of an xtpControlPopup. Should I expect it to? Or do I have to keep up with which item to check and which to uncheck? I have tried to also create xtpControlCheckBox when creating the CommandBarButtons and setting Style = xtpButtonAutomatic but that doesn't achieve the desired result either.