Did not see your earlier post but looks like cement yes render coat, plaster gypsum skim coat which for some reason has been painted with gloss paint then at a later date skimmed again.
So yes plenty of layers to attract moisture but is the damp really that bad? I can not see from this photo
Before I took all the paint off. To be fair it is looking better, this photo was 6 months ago. You can’t tell in the photo there is still some tide mark visible.
Looking back at the old photo I hadn’t realised it’s way better
Visible marks doesn't mean it's still damp necessarily. The damp will have moved anything soluble around with it which usually means you can still "see" it after it's dry.
Did not see your earlier post but looks like cement yes render coat, plaster gypsum skim coat which for some reason has been painted with gloss paint then at a later date skimmed again.
So yes plenty of layers to attract moisture but is the damp really that bad? I can not see from this photo