Hi,
we have fixed this issue in version 20.0, but in your existing plugin you can replace following function inside js/ppom-price.js file:
function ppom_get_formatted_price( price ) {
var decimal_separator= ppom_input_vars.wc_decimal_sep;
var no_of_decimal = ppom_input_vars.wc_no_decimal;
var formatted_price = price > 0 ? Math.abs( parseFloat(price) ) : parseFloat(price);
formatted_price = formatted_price.toFixed(no_of_decimal);
formatted_price = formatted_price.toString().replace('.', decimal_separator);
formatted_price = ppom_add_thousand_seperator(formatted_price);
return formatted_price;
}