Unable to access Administration URL using FQDN

Found this post, which is very close to my sitation but does not solve y particular issue:

As the post was almost 8 yrs old, I decided not to wake it up …
I want to access following 2 URLs:
Administration URL: https://www.domain1.com:10000/
Administration URL: https://www.test.domain1.com:10000/

Both this URLs are accessible via: https://192.168.0.100:10000 and all virtual servers are listed on the left hand side, I need to pick one of them and do the required configuration.

But if I can access the FQDN, I believe I will get only one system details to edit it. However, the no. of VM on LHS is not important here - what is important is to get it working and then I can decide which is better option for me.

So I am assuming, everything is working as expected: DNS, SSL, port forwarding etc.

Hope this extra information helps. Any suggestion will be highly appreciated.

Many Thanks,
Rav