Change Sharepoint Search Center URL

I changed my Search Center settings in the Admin Center according to the instructions listed below and I also changed the Search Settings from my homepage to the new URL, but the changes left the old state as is. What do I have to do so that I can change my search center to the following URL:
https://xxxx.sharepoint.com/SitePages/SearchCenter.aspx

To specify the URL of your Search Center in SharePoint, follow these steps:

1. Go to the SharePoint admin center and sign in with an account that has admin permissions for your organization. [1]
2. Under Search, select Open.
3. On the search administration page, select Search Center Settings.
4. In the Search Center URL box, enter the URL of the Search Center site. Example: http://companyportal/searchcenter/pages. [1]
5. Select OK. It may take up to 30 minutes before changes take effect. [1]

I wanted to open a ticket with MS Support, but when I entered my question, MS directed me to the Power Platform Admin Portal. But I can't enter a SharePoint topic there.