Replying to Look Pivot 14 - part of binding comes up?

I bought new bindings - Look Pivot 14. They were mountet by the seller. I only tried them in my room while doing a tailpress. I noticed that my boot comes up a bit in the front of the binding if i do tailpresses. The front part came up but not the whole plate. I rised the Z value a bit but nothing changed. Is it normal for pivot bindings? Is here anyone who has the same "problem"?

**This thread was edited on Nov 21st 2018 at 1:30:16pm