note The deisel and remix will be about average for rolling...
The high sides on creekers make it harder to get to the surface.

The slabsided wavesports (X, Z, EZ) were among the hardest to get up. The RPM was one of the easiest. I also recall one of the old school displacement hull creekers being even easier - I could hand roll it.

Shorter boats like your Jackson are sensitive to how your body is forward/back. If you lean back, you will bury the stern and have a harder time. This was especially true of the old slicey cartwheel boats.

Often WW boaters try to come up too fast. A slow, steady hip snap with a sweep roll often does well. If there are any sea kayakers around, try working with them. They have something like 30+ different rolls that they use - including sculling rolls that may work for you.

Also, see if your PFD gets in the way of your motion. Some are padded in inconvenient places.