Replying to Question about my boots

I know there are probably a million threads out there about boots being too big but I gonna ask for advice anyway
- ridden full tilts my whole life, regardless of them always feeling uncomfortable and too big (heel movement, toe bag shin bang)
- went to a boot fitter, tried on a good amount of boots, and got measured as a 26.5, I'm size 8.5 to 9 shoe
- Landed on a pair of Nordica speed machine 110s, they felt good and fitting in the store
-went home clipped into my skis and noticed how much I could move my heel when I really tried to, if I lean on my toes or nose butter I can get a good amount of heel movement. This has been the case for every boot I've been in so Im not sure if this is normal or not.

Should I go back to the store and maybe try the same model a size down? Or maybe look for another model that has a different fit in the same size? Any advice would be appreciated, maybe a footbed could help the problem too