Troubleshooting A-1 and overexposure

I started developing Ilford hp5+ in Ilfotec DD-x, and wasn't getting very good results. In fact, they appeared muddy and somewhat overdeveloped or overexposed. I couldn't tell which. I wanted to eliminate the cause of being a faulty shutter on the Canon A-1, a camera that was CLA'ed just a couple of short years ago. So, I ran a test between that camera and an AE-1 shooting them both with hp5+ at the same settings: 1/15 second exposure time and f/5.6 aperture. Both shot at box speed, then developed on the same reel in the same developer. As it turns out I couldn't tell much difference between the two strips, but the A-1 might have been slightly more exposed. Not more than a fraction of a stop from what I can tell. In any event, here are the results. My conclusion is that DD-x doesn't develop hp5+ very well. Not the way I develop, anyway.