Additional Information
This behavior can also occur when trying to assign a boolean value to a front-panel control being referenced as type Control, even if it is typecast to Boolean using the
To More Specific Class function - this is because the control reference isn't being cast to a boolean with a specific mechanical action.

Because the property node cannot tell if the control is being typed as a latching or switching boolean, the property node is unsure of the exact set of properties to provide/exact kind of data to expect, and defaults to coercing the data passed to it to Variant.