Well, well, no need to go further, I got the answer (not obvious
for me)
In fact, I must have selected a setting somewhere sometime (no memory) and once I start directly Nickel, once I start KSM first (from there the different results). Now I have to modify this setting to start everytime from KSM. First finding it...
EDIT: OK I found it:
runsettings.txt
Thanks for your help.