Ok I got the problem (I mean a little) Once I click on Develop button, I go back to Photo Persona and the file is now showed : RVBA/16 profoto RGB
If i click again to go back to the raw dev button : Develop Persona, I have a good histogram and the picture format is : RVBA/16 - Profoto RGB not anymore in RVBA 32bits.
I think the dev tool must "detect" the good numbers of bits of the picture to avoid this problem ?!
It's a little stupid to do that but I found a fix : open .NEF, then click develop to go to Photo Persona, then click on the button Develop Persona to go back to the RAW develop tool and have a good histogram ;) :) :) :)