Auto filled dropdown value not recognised

Have set up having two dropdowns showing the same values when a value is entered in either one, as per your formulas you gave me, thanks

In fieldname2:

(function(){
var f = getField(3).jQueryRef();
if(fieldname1 == 0 ) f.find('[value="0"]').prop('selected', true);
if(fieldname1 == 1 ) f.find('[value="1"]').prop('selected', true);
if(fieldname1 == 2 ) f.find('[value="2"]').prop('selected', true);
})();

And in the fieldname4:

(function(){
var f = getField(1).jQueryRef();
if(fieldname3 == 0 ) f.find('[value="0"]').prop('selected', true);
if(fieldname3 == 1 ) f.find('[value="1"]').prop('selected', true);
if(fieldname3 == 2 ) f.find('[value="2"]').prop('selected', true);
})();

Both of these dropdown values are used in different separate calculation fields. I am having trouble with one of them. The dropdown that is changed by the formula above is not being recognised as a number in it’s following calculation field function. It is only the dropdown that is actually physically changed that is recognised in it’s one.

How can I get it to be recognised?

Thanks