Had that been the case the satellites,spies,starlink etc would have caught their movement.Usa is not fool to take a b2 across the continent and bomb an empty facility in iran.Reformists are now angry on conservatives hence basij forces have taken over the civil administration.
Iran has too much infiltration with pro american,shah loyalists and pro israel just like india has soros agents everywhere in admin and media.
You think burger munchers are all powerful.

If underground facility is possible why aren't underground roads?
I'm not saying this happened, just that it's entirety possible.