Hi @studiokrass,
Some plugin, theme or other code seems to modify your Billing Country field in the checkout into a format the Mollie API is not accepting.
I see that your site only sells to Belgian customers. Did you set this country in WooCommerce or any other way?
You can try to add this filter to your themes functions.php file to rewrite the field information:
add_filter(
'mollie-payments-for-woocommerce_is_available_billing_country_for_payment_gateways',
function ($billing_country) {
$billing_country = 'BE';
return $billing_country;
}
);
But it would be better to find out why the field was modified in the first place.
Can you please (without the filter) disable all other plugins and activate the storefront theme to see if the issue persists? Thanks!
Kind regards,
Niklas