that’s normal. that’s just how cascade shadow maps work. you have a small edge sticking out, that does not cast a full shadow. also the buildings are at an angle. so the cascade shadow map will cast angled shadows.
the only way to reduce it is to raise r.Shadow.MaxCSMResolution or use a different shadow method. vsm has higher resolution by design and ray traced shadows eliminate this issue altogether. vsm has a memory cost and raytraced shadows obviously a computation cost.
the other way would be to reduce the edge and use some shader trickery to make it look like an indent.