Replying to Boot help for new park skier

I just recently purchased some 26.5 soloman spk 90's (from previously having an old used 28.0 sized boot). They are great for the most part, but off some jumps I'm landing back seat, and this is mostly being caused from not clearing the knuckle on most jumps, but i tend to land backset fairly often, my toes will go to the front of my boot, and I will have less edging control, is this a boot sizing error or would a custom footbed help?