You unit has a separate "sensitivity" for DI, 2D, and SI. I have to set my DI sensitivity much higher than my SI in order for it is show up better. I run my SI sensitivity on 10-12 and the DI sensitivity on 15-16. Just turn up your DI sensitivity and it will show up better.

From your images, the DI is picking up the fish. The DI will show the fish as small specks and the 2D will show large arches. You last picture looks really good to me. You can see the shad ball and several fish in the DI screen that match perfectly with the 2D screen.