@givemeawhisky thank you so much for your help so far!
I totally get what you mean, but I still can’t get it to work!
I have changed to field type in the DB to Text, and this is the function now:
export function sumRevenueAmount (){
var total = 0
total = (
Number($w('#inputRevenueItem1Amount').value)+
Number($w('#inputRevenueItem2Amount').value)+
Number($w('#inputRevenueItem3Amount').value)+
Number($w('#inputRevenueItem4Amount').value)+
Number($w('#inputRevenueItem5Amount').value)+
Number($w('#inputRevenueItemAAmount').value)+
Number($w('#inputRevenueItemBAmount').value)+
Number($w('#inputRevenueItemCAmount').value)+
Number($w('#inputRevenueItemDAmount').value)+
Number($w('#inputRevenueItemEAmount').value)+
Number($w('#inputRevenueItemFAmount').value)+
Number($w('#inputRevenueItemGAmount').value)+
Number($w('#inputRevenueItemHAmount').value)+
Number($w('#inputRevenueItemIAmount').value)
);
$w('#inputRevenueItemTotalAmount').value = total.toString();
}