Create top level domain on subserver when subdomain exists crashed BIND

SYSTEM INFORMATION
OS type and version Almalinux 8.6
Virtualmin version 7.1

Hi, I have some subdomain as top level server for this top level domain on this server like:
one.example.com, two.example.com, etc are in top level server.

Now I want to create example.com as a sub server of my default virtual server default.virtualserver.com
When I create the virtual server, BIND service is stopped and I get this error on systemctl status named

 _default/example.com/IN: bad zone
named.service: Control process exited, code=exited status=1
named.service: Failed with result 'exit-code'.
Failed to start Berkeley Internet Name Domain (DNS).

I then removed the virtual server, restarted named, and named.service is back to normal. When I recreate the virtual server again, BIND is error again.

How can I create the example.com as sub-server?