I'm assuming, that the black stuff on the walls is a rising dump.
3 external walls have this problem, however 1 wall does not have this problem. Problematic walls are in a direct contact with a concrete (driveway, walkway). Non-problematic wall has a soil. I'm thinking, that the concrete is preventing wall breathing or the concrete is transferring moisture to the wall.
Bad wall.
Bad wall.
Good wall.
What I was thinking is dug up a trench around the house and fill it with rocks. I would not go full "french drain" with a pipe inside of it. Just a rocks between house and concrete. To let the wall breathe and let any water potential water drain quickly into lower levels.
Do you thing it would help?
Idea: