How can I Change the Username Displayed on the Supplier Portal HomePage Welcome Message

My client has reported multiple cases from suppliers where the username displayed on the Supplier Portal Home Page does not change even after changing the name in the Contacts tab from Company Profile. We are having trouble figuring out why, because this problem has not occurred in the test environment and is only happening in the production environment. We have checked that the changes to the company profile have been approved.

What could be some possible reasons and how can I change the displayed homepage username for the production environment?

The screenshots below are from the test environment, where we succeeded in changing the name displayed on the home page.