[akimball]

I think homes with back-plastered walls can be essentially faraday cages, depending on the aggregate content of the plaster. I have very dodgy 4g/5g unless I stand by a certain window, or go outside of the older part of my house, while the new part (metal roof, wallboard) has outdoor-like reception.

[vel0city]

Its not even just the aggregate of the plaster, often the walls practically have chicken wire supporting the plaster in places.

But even then, its really not too crazy to find yourself inside any kind of building and not having strong cellular connectivity. Lots of commercial buildings I've been in have had some pretty poor cellular connectivity in any internal room; they've got tons of concrete and plumbing and wiring all throughout it!