Hi @picaland,
Thank you for your patience and collaboration in testing this. I’m thinking the problem lies in the live site connecting to WordPress.com.
On occasion, WooPayments might become disconnected from WordPress.com. To fix this problem, you can use Jetpack to reset the connection so that it works again.
To reset the connection, you can use the free Jetpack plugin to forcibly break the connection between your site and WordPress.com. Such an action will allow you to disconnect and reconnect your site to — and associate your WooPayments account with — your WordPress.com account.
Here’s how you can do that: https://woocommerce.com/document/woopayments/our-policies/connection/#how-to-use-jetpack-to-change-the-wordpress-com-account. Just make sure to reconnect to the same WordPress.com account you’re using, as you don’t want to change the account, just reset the connection.
If this doesn’t work for you and you still need help, please contact us at WooCommerce.com > My Account > Support. Please include a link to this forum thread so that we can keep track of what’s already been done. We will be able to help you further there.
Thanks!
-OP