DNS resolves machines on network but does not resolve virtual machines

Question

I have an issue with my internal network. I have a proxmox server with multiple VM on it; I also have other servers and NAS on the same network. I wanted to have a local domain name, so I created a LXC container which acts as a DNS server inside proxmox. I installed alpine on it and BIND DNS. I configured the DNS server as follows:

• File /var/bind/pri/internal.gpap.zone

    $TTL 86400
    @       IN      SOA     dns.internal.gpap. root.internal.gpap.  (
                                          2022040802 ; Serial
                                          28800      ; Refresh
                                          14400      ; Retry
                                          604800     ; Expire - 1 week
                                          86400 )    ; Minimum
    @                               IN      NS      dns
    ns                              IN      A       127.0.0.1
    dns                             IN      A       192.168.1.4
    internal.gpap                   IN      A       192.168.1.1
    onlyoffice.internal.gpap        IN      A       192.168.1.118
    rocketchat.internal.gpap        IN      A       192.168.1.150
    nas.internal.gpap               IN      A       192.168.1.113
    proxy.internal.gpap             IN      A       192.168.1.5

• File /etc/bind/named.conf

    options {
            directory "/var/bind";
            allow-recursion {
                    127.0.0.1/32; 192.168.1.0/24;
            };
    
            forwarders {
                    8.8.8.8;
                    8.8.4.4;
                    1.1.1.1;
            };
    
            listen-on { 127.0.0.1; 192.168.1.0/24; };
            listen-on-v6 { none; };
            pid-file "/var/run/named/named.pid";
            allow-transfer { none; };
            dnssec-validation auto;
    };
    
    zone "." IN {
            type hint;
            file "named.ca";
    };
    
    zone "localhost" IN {
            type master;
            file "pri/localhost.zone";
            allow-update { none; };
            notify no;
    };
    
    zone "127.in-addr.arpa" IN {
            type master;
            file "pri/127.zone";
            allow-update { none; };
            notify no;
    };
    
    zone "internal.gpap" IN {
            type master;
            file "internal.gpap.zone";
    };

The DNS server is running and it correclty resolves nas.internal.gpap or onlyoffice.internal.gpap. These two are individual machines on the network. However when I try to resolve other LXC containers/Linux VM on the same proxmox server (for example rocketchat.internal.gpap) it does not work. Some other notes:

• I can correctly ping all the servers (physical and virtual) and I can access all the LXC containers/Linux VM through their IP address.

• Nslookup shows:

  *** UnKnown can't find rocketchat.internal.gpap: Non-existent domain

• The VM are connected to internet through a linux bridge inside proxmox.

It is really strange that the DNS resolves physical machines but does not resolve VM on the same server. Can someone help? Thank you so much!