Issue Unable to install Let's Encrypt certificate for temporary domain

[tuba-truba]

Server operating system version

CentOS 7

Plesk version and microupdate number

Plesk Obsidian Web Admin Edition 18.0.53 Update #1

I tried creating a temporary domain to setup a new site and got the following: sharp-alien.SERVER-IP.plesk.page
During setup I got an error message:

An issue occurred while securing the domain sharp-alien.SERVER-IP.plesk.page:

Could not issue a Let's Encrypt SSL/TLS certificate for sharp-alien.SERVER-IP.plesk.page.

The authorization token is not available at http://sharp-alien.SERVER-IP.plesk.page/.well-known/acme-challenge/55hi-dsadsadsadadsadsa.
To resolve the issue, make sure that the token file can be downloaded via the above URL.

The temporary domain is not accessible with the following error

NET::ERR_CERT_COMMON_NAME_INVALID

For some reason it the temporary domain is shown to have a certificate of one of my other domains.

The other domain is also on this server, has it's on (non-Let's Encrypt) cert, but I never had issues adding new domains before (temporary or otherwise).

Important thing to mention is that my plesk domain looks like this https://plesk.mydomain.com:8443/, and the certificate that's detected on the temporary domain belongs to mydomain.com

I tried disabling SSL/TLS support but got the same error. I'm essentially unable to access the temporary domain and that's why Let's Encrypt fails as well.

Anything obvious that I'm missing? Any help is appreciated and I can provide more info if needed.

 

[Peter Debik]

Does a ping on the temporary domain lead to the correct IP address of your server?

 

[tuba-truba]

Does a ping on the temporary domain lead to the correct IP address of your server?

I get "Request timed out" when pinging sharp-alien.SERVER-IP.plesk.page

 

[Peter Debik]

Obviously the nameserver entry for the domain is missing. Can you try to create a new plesk.page-domain and see whether that is accessible?

 

[tuba-truba]

Obviously the nameserver entry for the domain is missing. Can you try to create a new plesk.page-domain and see whether that is accessible?

I tried, but I still get the same result.

The page does get created, and there's a screenshot of the default Wordpress theme in Plesk dashboard. But after that it becomes inaccessible.
I really think it's because of the wrong SSL cert it gets assigned, but I don't know how it happens (it hasn't happened for other domains) and not sure how to fix it.

 

[Peter Debik]

The "wrong SSL cert" is a result of the situation where no domain SSL cert can be assigned. In that case the fallback - the server certificate - is set. That is a symptom, not the cause. The cause is that for some reason the domain is not linked to a nameserver entry. Else you would be able to at least ping the domain using the domain name. In order to issue a domain-validated SSL certificate, the domain must be active and accessible through the internet on your server.

Is your server publicly on the Internet or are you behind a NAT router? Is the IP address in the temporary domain your public IP address or your local IP address behind your router?