Confused by DNS configuration

I’m testing out Cyberpanel, as I’m interested in the potential speed benefits.
I did a standard install, Ubuntu 20, but chose not to install FTP. Otherwise just agreed to what it suggested.
I put a subdomain on the server to test. lite.mydomain.com
But when I was trying to connect to my original server, to copy files across, mydomain.com, I couldn’t connect. I finally figured out that mydomain.com is also resolving to the server I installed cyberpanel on.
dig mydomain.com, mtr mydomain.com all point to the public ipv6 address of the server.
Surely this is wrong? I should be able to have my main domain and the subdomain on different servers? If I disable PowerDNS with systemctl, then the domains resolve correctly

As I’m using external DNS, I don’t need PowerDNS. Can I just apt get purge it? Or should I systemctl disable it. Or do I need to go back to the beginning and reinstall without DNS?

Did the following.
apt remove pdns-backend-bind pdns-backend-mysql pdns-server
systemctl enable systemd-resolved
systemctl start systemd-resolved

It really wouldn’t matter if you’re using CyberPanel or any other control panel / webserver as this would be a function of only your DNS.

If you registered your domain at NameCheap, Godaddy, or any other registrar, you will have the option to manage DNS records there for that domain name.

So, if you want MYDOMAIN.com to point to a site on one IP address and LITE.MYDOMAIN.COM to point to a different address, you’ll have to specify that with your A records. For example:

A MYDOMAIN.COM 123.34.232.111
A LITE 22.212.32.12

The second entry will resolve to LITE.MYDOMAIN.COM at the separate IP address.

It wouldn’t matter if you fiddled with PowerDNS as it’s not controlling anything.

If you wanted to use this new CyberPanel server as a DNS server for your domain, that’s a very different situation. You would have to create the servers as a Primary DNS server, create custom nameservers at your registrar (ns1.mydomain.com, ns2.mydomain.com).

If you’re just testing cyberpanel, don’t do the latter option. This is a whole bunch of work. It’s also potentially very disruptive to your other services such as mail (MX records) if that’s being currently managed by your current DNS.