Oh sorry I had not verify my parameters

! now all is ok !
In my ".kobo\kobo\Kobo eReader" I had :
numPartialUpdatePageTurns=90
And my my ".kobo\nightmode.ini" I had :
refreshScreenPages =4
I think it's the default parameter after update night mode v9... now it's ok after change it to 90 !
For RobertJSawyer the answer brought here
https://www.mobileread.com/forums/sho...185660&page=51 is :
"
I've The answer is "Setting numPartialUpdatePageTurns=11 still works on my Glo with fw 3.1.1, so it is not a limitation of the firmware. (I don't have night mode installed.)"