Hostname on debian

[Rob24h]

I have a cloud pbx, running 15.5 SP6 and I am wondering what the hostname in debian should be.
Phones should connect to the PBX on the domainname: pbx01.mydomain.com

When I type in console: hostname -d
It responds: domainlocal

When I open: etc/hosts
It says: 127.0.1.1 pbx01.domainlocal pbx01
127.0.0.1 localhost

When I open: etc/hostname
It says: pbx01

Is this all correct?
I am asking this as I can see warnings in my activity log ever since I added a new phone.
The warning is: Warning: 499 pbx01.domainlocal "Not available"

 

[Rob24h]

Just to add, this was installed from the 3CX ISO (when it was upgrade 1 or 2 I think).

 

[Rob24h]

Can anyone help me with this?

 

[DSXVOICE]

The hosts file should probably look like this:

127.0.0.1 localhost pbx01.domainlocal pbx01