Can't add Form Groups into a Conditional Region

I’ve added a conditional region to a Bootstrap generated form in order to toggle the visibility of a group of fields, but for some reason, I cannot move the Form Groups into the Conditional Region element in the App Structure.

I moved the form groups into the conditional region via the code view and it seems to be functioning OK. But I can’t reorder any of the form elements that were manually added to the conditional region in the App Structure window.

Does anyone know if conditional regions have limitations on where they can be used/added?