Lime-gypsum plaster crumbly and therefore defective?

So, today I really threw myself against the walls, nothing got dented and it also feels solid. At some sockets, the plaster was thicker over it, so more force was needed to break it through. It did crumble anyway, but it seems to have a certain compressive strength. It was probably because the plaster layer above the sockets is thinner.

Looks normal. The plaster hardens over time. It can take a few weeks for the final hardness and durability to develop.

Looks normal. The plaster hardens over time. It can take a few weeks until the final hardness and resistance is developed.

Has the plaster been on since October?

Then it has reached its strength.

The plaster looks completely normal according to the pictures and the information! If there are no other indications, that is fine!

The walls will still be primed before painting, so it will crumble less / not at all. Everything else can't be saved now anyway, even if the mixing ratio is not correct.