Hi Panaromix,
From your PDF, I can see in the first screenshot that you did apply some changes in the "Numbers" tab of your Override Settings window. The "Number Range" option (which you set to 0-100), together with the "Order" option (set to "Numerical (forward)") causes all your Quantity lessons to always start from 0.
Since you said you intend to keep the Quantity lessons as is, there is no need for you to do anything in the "Numbers" tab of the Override Settings window (i.e., which governs all Quantity lessons).
Kindly try disabling all the options in the "Numbers" tab and see if that fixes the problem.