No valid A or AAAA record

When trying to login to zzz.my-domain:8080 I get the following error: "This site can’t provide a secure connection"
When generating SSL (letsencrypt)for the server, following error occurs: "No valid A or AAAA records could be ultimately resolved for xxxxx.yyy.se. This means that Let's Encrypt would not be able to to connect to your domain to perform HTTP validation, since it would not know where to connect to.
No A or AAAA records found.

Any ideas how to troubleshoot? A records is not my strong side...
"intoDNS" show no errors nor any recommendations.

However, I can login from my 6 year old pad, without ssl.
Using latest ispconfig guide.

 

Configure this at the domain's dns server.

 

Thanks for your answer.
However that is already done, and according to the hosting provider the A record is correct configured