Question about plaster flaking above the baseboard

Hello everyone,
I am completely new here in the forum and first of all, greetings to everyone! :)
We have been searching for a house in Berlin for some time now and have already seen quite a few things (wet basements, asbestos facades, etc.). This weekend we are viewing a house from the 1930s. From the outside, my wife took a photo that raises questions. What could cause these plaster flakes, and what should I pay attention to during the house viewing?


Best regards, Tobias

As a layperson, I would say it felt like it was or is wet there. Whether from a leaking gutter/pipe, rising water, a cold bridge in the corner, and all this combined with little sunlight due to the tree