The porch looked great. No cracks, sloped away. And it faced east. Most weather around here comes from the west, north and south unless we get a Northeaster.
Just seemed a strange place for moisture and it was not the typical coloration of stain.
David, I have seen familiar stains like that on block before.
Since I can’t see the whole picture of conditions, I am only guessing.
Those appear to be stains created by wet plywood, OSB, regular lumber etc., leaching through the block work and creating that dirty rusty water stain. Water and/or moisture is negating the Building Envelope in that area somehow.