It may be intentional but the only room my dwellers don't level (either in levels or SPECIAL) in is the Radio Room. Dwellers sent there don't gain anything.

I understand that these rooms give happiness and attract new dwellers but is there a reason that dwellers assigned there don't level up?

I did search for a similar topic but the search function returned zero hits for "radio" so I'm either doing something wrong or there's something wrong with search.

Yeah, I just don't think it gives experience. I really hope they will fix this so it gives a chunk of do every time you get someone to come.

The second one. There's a half dozen or so threads about it.

I concur. Storage Room or Living Quaters does not give XP. But working on Radio Studio should give XP to dweller. If not, there is no place where dweller with high Charisma can level up like other SPECIAL's. They are working and they produce new dwelllers. They deserve XP.