Domain Redirection Issue in Carbonio CE: Redirecting to Private IP Instead of Public Domain

I’m facing an issue with my Carbonio CE setup related to domain redirection. I’ve configured everything to use a public DNS hostname, such as mail.example1.com. However, after logging into the web interface, the system redirects to the local server IP (private ip) instead of keeping the public domain in the URL.

For example:

I go to https://mail.example.com, which works fine.
After entering my credentials, it redirects to https://192.168.x.x/static/login/ instead of https://mail.example.com/static/login/.
Similarly, after login, it continues redirecting to https://192.168.x.x/carbonio instead of staying at https://mail.example.com/carbonio.

In my nginx.log, I’m seeing the following error message:

2024/09/25 15:28:56 [error] 53530#53530: *87242 recv() failed (104: Connection reset by peer) while reading response header from upstream, client: 192.168.45.50, server: mail.olddomain.xyz, request: "GET /zx/login/supported HTTP/2.0", upstream: "http://127.78.0.1:20008/zx/login/supported", host: "192.168.x.x", referrer: "https://192.168.x.x/static/login/"

In my installation, i create a test DNS using dnsmasq (mail.olddomain.xyz), but I change the DNS to the mail.example.com following these steps:

https://community.zextras.com/how-to-change-the-hostname-servername-of-your-carbonio-community-edition-server-carbonio-ce/

For additional info:

/etc/hosts: 192.168.x.x mail.example.com mail

zimbraMtaMyNetworks: 127.0.0.0/8 [::1]/192.168.x.x/24

zm_lookup_handlers  https://192.168.x.x:7072/service/extension/nginx-lookup; 

{
"bind_addr": "192.168.x.x"
}

nat_1_1_mapping = "PUBLIC IP"

dnsmasq is disable

zmhostname
mail.example.com

zmcontrol status
Host mail.example.com
amavis Running
antispam Running
antivirus Running
directory-server Running
mailbox Running
memcached Running
mta Running
opendkim Running
proxy Running
service webapp Running
service-discover Running
stats Running
config service Running

dig mx mail.example.com
example.com. <...> IN SOA <...>

dig example.com
;example.com. IN A


;; ANSWER SECTION:
example.com. <...> IN A <Public IP>

dig mail.example.com
;mail.example.com. IN A

;; ANSWER SECTION:
mail.example.com. 0 IN A 192.168.x.x

Another issue I’ve noticed is that the chat and video call functionality only works when I set the NAT 1:1 mapping to the private IP (192.168.x.x)

nat_1_1_mapping = "192.168.x.x"