Can't acess domain.tld:10000, only serverip:10000 [Suddenly Stopped]

Hey guys!

Until last week I was able to browse mydomain.tld:10000 but today it is not working :(.

At least I'm able to browse via serverip:10000. I have already tried to reboot my server in order to "fix" that, but.... didn't work.

The only weird thing I could see was my log files (sent via mail):

Oct 30 14:03:07 server systemd: Reloading.

Oct 30 14:03:07 server systemd: Reloading.

Oct 30 14:03:07 server systemd: Reloading.

Oct 30 14:03:07 server systemd: Reloading.

Oct 30 14:03:07 server systemd: Stopped firewalld.service.

I have never seen this before. And I don't know why, but:

Oct 30 16:58:43 server lfd[20972]: DynDNS: Lookup for [MYNOIP.COM] failed