I've been using various Crank Brothers pedals for a while now and like them a lot. I got a new pair of shoes (Shimano MT21, if it matters) and installed a set of the unused cleats that I had in a box. With this new combination I have absolutely no float in the pedals, which is really odd because general CB pedals have an absurd amount of float and I set them up with the maximum float configuration.

My old shoes had these cleats (the "premium" model, I believe):



but with the new ones I used these (the basic model, I believe):



It doesn't seem like that should matter.

I didn't use the plastic shim. Is it possible that is causing the problem? Maybe there's not enough space between the cleat and the shoe?

Has anyone else had this issue?