WordPress (Payment) Error Saving Customer. Reason:

Error Saving Customer. Reason:

Dear Sir/Madam,
Good day!
Thank you very much for taking the time to open and read this letter.

I have been using WordPress for the development of this website for two years, and this year we decided to add a new feature that would benefit the Plataforma Makobo’s Organization – The Payment and Shipping option for our users to purchase and receive our product.

A couple months after adding that feature, the website suddenly decided to display an error when the our client decided to purchase one and is redirects to the payment page that shoes a message that says:

“Error saving customer.
 Reason: 
Payment error:”

This error doesn’t affect the website, the website still works properly and the user can finish his payment
We attempted to clean our cookies and test it again; however, it continued to display the same error;
I would like to know how can I solve this problem?
PS: This happens to all the payment gateway plugins that I have, paypal, visa, mastercard, etc.
All three plugins show the same error (which is unusual to happen);
(So, I am assuming that the problem is not with the plugin).

We also attempted to change our payment Gateway Plugin by using the M-Pesa WooCommerce plugin and finally the PayPal plugin (all plugins support Mozambique, the country where the Plataforma Makobo’s headquarter is located);
however, the webpage continued to display the same error and did not redirect the user to the payment page.

You can find the error image here:
https://i.postimg.cc/m2Rw43tv/error-wordpress-payment.png

For this reason, we are reaching out to The WordPress Technical team to ask for an urgent support regarding this problem.
We welcome any support The WordPress Technical Support Team can offer.

The page I need help with: [log in to see the link]