It's wall board with vynl stuck on somtimes it is glued on and is almost impossible to get off or it is pasted on and comes off quite easily.
If it's damp and it sounds like it is the paper comes off easily until it gets to a dry part then it tares.
If you can peel it off you can re vynl it using heavy duty vynl paste.
If it feels like pimples under the vynl almost certainly you have a leak and need to sort that out first.
No its just like it's been on to tight so has a wrinkle in it, we are only talking 2cm by 1cm square on a patch in bedroom.
It's been damp tested in recent service, no damp or leaks, it was just something that I wondered why vynl covering does that.