Wall plastering in the basement

Hello,

I have a question about the wall plaster in our basement rooms. Our painter plastered our entire house back then with gypsum plaster from Einza. The packaging states that the plaster is also suitable for damp rooms such as bathrooms or kitchens. The painter said we could also plaster the walls in the basement with it. They had quite ugly holes. I did this and only found out afterward that gypsum plasters should not be used in basements at all. However, the painter was sure that it was okay because our basement is dry. So far (now about 2 years) nothing can be seen. We painted over it and everything is still nice and white. Now, however, I have another wall facing outside, which looks a bit yellow. I would actually prefer to use a different plaster here because of possible moisture. However, I do not know if the wall is actually damp. At least it does not feel like it.

My questions now:
a) Was it okay to use the gypsum plaster for the basement at all?
b) Which plaster should I use for the wall facing outside (window in the wall)?

I would be very happy to receive answers!

PS: I have uploaded a picture of a finished plastered wall in the basement and one of the mentioned wall facing outside.

So you have a masonry basement, correct?

Lime-cement plaster belongs on that.

But honestly: the plastered surface already looks pretty dreadful...