Masonry crowns - How to seal properly?

Hey,

we suspect that the masonry crowns were probably not properly sealed according to the recognized rules of technology. Therefore, the following question: how should that be done? I have read about "Mörtelschlag". But in our case, the topmost rows were always sealed with the same material as the bottom rows. With the horizontal barrier against rising moisture, made of some kind of rubber / bitumen-like material.

We were told that the first row of bricks should always rest on this horizontal barrier. But in our case, the last row of bricks between the bricks and the floor slab was also lined with it. No sign of mortar.

Defect or no defect, who knows? I simply can’t find any explanatory words on the internet about this.

Thanks

What does the architect or expert say?

If the concrete ceiling is on top, it probably isn't a wall crown, is it?

In our case, it is suspected that the masonry crowns were probably not properly sealed according to the recognized rules of technology.

On the one hand, I see it that way too

If the concrete ceiling is lying on it, it is probably not a masonry crown, right?

and on the other hand, I do not read anywhere here which damage initiated the suspicion of the defect (?)

Potential draft is the issue. Why shouldn’t this be a wall coping? The last row of stones is referred to as wall coping, and it usually has to be sealed, right?!

It may be the last row before the ceiling. But it is not the top edge. Is the wall plastered on the outside?