Bug with "Stage" field and probability

Bug with "Stage" field and probability

There is a bug with 4 opportunities that were created recently : when we put "Qualification" in the "Stage" field, the probability should be 10% (I checked in the field description and the setup is correct).

But this does not work and for this 4 opportunities, the probability is 0% !!! I tried to changed it manually : I did enter manually the stage and the display is correct : 10%. But when I save the opportunity and open it again, the probability is again 0% !!!!

Could you please help and explain how to solve this bug ????

Thanks and regards,

Olivier