I have already contacted support and they refuse to help because they claim it is a developer problem.  Here is the issue.
Last week, I updated our ssl certificate for a custom domain to be served using experience cloud.  After publishing the change:
When I visit my custom domain, I get the certificate for a COMPLETELY DIFFERENT SITE.  This is not even a site I own.  The certificate that I receive is not listed in my certificates in salesforce.  It is as if the CDN has its wires crossed.  I have switched back to the old cert and still receive the wrong certificate when I pull up the site by custom domain.  Has anyone ever had this happen?  How do you get Salesforce to even look at it?

Hi.

We need 3 Certifcates
1.SSL Certificate.
2.CA Intermediate Certiticate.
3.Root Certifcate.
If you dont got the root certitifcate from the provider,you can download it from the provider website/home page.

Uploading CA-Signed Certiifcate as follows.
1.Open a Notepad.
2.Paste each certificate as per below order into the note pad.
-----BEGIN CERTIFICATE----- 
(SSL certificate) 
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE----- 
(CA Intermediate certificate) 
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE----- 
(Root certificate) 
-----END CERTIFICATE------
3.Save the notepad as "sitesSSL.cer" or "xxx.cer"
4.Now goto Settting>Security Control>Certtificate and Key Managment
5.Select the certificate in which you want to upload.
6.Upload the newly created sitesSSL.cer
7.If no errors than your done and chek your site from the browser whether you have a lock sign in the browser or not.
cheer
suresh
 

I have already contacted support and they refuse to help because they claim it is a developer problem.  Here is the issue.
Last week, I updated our ssl certificate for a custom domain to be served using experience cloud.  After publishing the change:
When I visit my custom domain, I get the certificate for a COMPLETELY DIFFERENT SITE.  This is not even a site I own.  The certificate that I receive is not listed in my certificates in salesforce.  It is as if the CDN has its wires crossed.  I have switched back to the old cert and still receive the wrong certificate when I pull up the site by custom domain.  Has anyone ever had this happen?  How do you get Salesforce to even look at it?

Hi.

We need 3 Certifcates
1.SSL Certificate.
2.CA Intermediate Certiticate.
3.Root Certifcate.
If you dont got the root certitifcate from the provider,you can download it from the provider website/home page.

Uploading CA-Signed Certiifcate as follows.
1.Open a Notepad.
2.Paste each certificate as per below order into the note pad.
-----BEGIN CERTIFICATE----- 
(SSL certificate) 
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE----- 
(CA Intermediate certificate) 
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE----- 
(Root certificate) 
-----END CERTIFICATE------
3.Save the notepad as "sitesSSL.cer" or "xxx.cer"
4.Now goto Settting>Security Control>Certtificate and Key Managment
5.Select the certificate in which you want to upload.
6.Upload the newly created sitesSSL.cer
7.If no errors than your done and chek your site from the browser whether you have a lock sign in the browser or not.
cheer
suresh