Problems with the insulation?

I am not quite sure if I am in the right topic here, but a friend of mine recently moved into a new apartment. The storage room there, which is directly on the outer wall of the house, is very soft, feels like styrofoam, and is already showing strong signs of molding... is this due to incorrect insulation? Can she talk to her landlord about it?

Thank you very much in advance

Hello Grekko,
I wanted to write something about it just now but I see that you are banned and so I believe I don’t need to write anything else to you regarding this. Or can you still read in the forum? Just get in touch via my PM.