Carpentry Question - Stairs not to code per inspection report

[Kevin Gallagher]

My inspection report came back saying that the stair stringers are not properly secured to the floor framing. The stringers and floor joists run parallel. One stringer is nailed directly to the joist and the other has (2) small pieces of of 2x4 between the stringer and joist to make up the gap between the two. See photo below. 

Is the concern here that the stringer does not butt up perpendicularly to the floor framing? Just trying to understand the issue a little better. 

Any input on this would be greatly appreciated.