[ She would usually say that she's confident in defending herself without a Persona but she doesn't have her gun not combat core. It sucks feeling like a civilian doll when she shouldn't be!! ]

I cannot be certain for danger levels, but I assume there could be something like a jammer in this place that could somehow block Persona summoning. That's what I mean by source. It would be easy to get rid of if it is simply an item, but from the number of things that surprise me about this place as a whole, I cannot be too certain.