The multiplication of the two hidden fields is 1

Hi, i have problem with hidden fields, that returns an incorrect values:

1) I have a field in which someone enters an initial value.
2) In the next step, select one or more of the five checkboxes.
3) After clicking on the checkbox field, two fields are always displayed (for example checkbox-2 and select-1).
4) Other unselected checkbox field are still unselected and linked fields are hidden.
5) There is a problem here, because I have to take into account all variants in the calculation field (it is possible that the user checks all the options).

My formula is:
{number-1}-
({checkbox-2}*{select-1})-
({checkbox-3}*{select-2})-
({checkbox-4}*{select-3})-
({checkbox-5}*{select-4})-
({checkbox-6}*{select-5})

My example with 2 checked options:
{number-1}- / Filled value is 1000
({checkbox-2}*{select-1})- / Selected value in checkbox-2 is 40 and in select-1 is 2
({checkbox-3}*{select-2})- / Unselected checkbox and unselected selectbox
({checkbox-4}*{select-3})- / Unselected checkbox and unselected selectbox
({checkbox-5}*{select-4})- / Selected value in checkbox-5 is 100 and in select-1 is 3
({checkbox-6}*{select-5}) / Unselected checkbox and unselected selectbox

Therefore, the correct calculation is 1000 – (40*2) – (0) – (0) – (100*3) – (0) -> so the result is 620.

But form showing value 617. The hidden lines like ({checkbox-3}*{select-2}) counts the Forminator as 1 instead of 0.
Forminator calculate 1000 – (40*2) – (1) – (1) – (100*3) – (1).

How its possible? And how i can fix it please?