Basement wall - What needs to be done here?

Can someone explain to me what is going on with our basement wall? What needs to be done to fix the problem?

On the outside is the entrance staircase. The house is from 1954, so I cannot say anything about possible drainage. We have measured the moisture; it is completely dry. The device shows 1-2%.

Can someone explain to me what is going on with our basement wall?

It seems to be getting damp from below. The moisture is rising upwards.

What should be done to fix the problem?

To find the cause.

On the outside is the entrance staircase.

Then show the corner outside. Usually, a swamp has formed there because the drain is blocked due to lack of maintenance.