you can add this to your function.php of your child theme
function theme_default_option_mphb_thousand_separator() {
return '.';
}
function theme_default_option_mphb_decimals_separator() {
return ',';
}
add_filter( 'default_option_mphb_decimals_separator', 'theme_default_option_mphb_decimals_separator' );
add_filter( 'default_option_mphb_thousand_separator', 'theme_default_option_mphb_thousand_separator' );
you can customize the separators as you like. in this example is the thousand separator a “.” and a comma for the decimals.