NC and collabora running behind nginx revers proxy with only IPV6 public adress

I am running NC and Collabora on an TrueNas Scale.

NC Version: 28.0.3
Truenas Chart Version: 1.6.58

collabora Version: 23.05.9.4.1
Chart Version: 2.0.8

ssl is terminated at the nginx reverse proxy. Traffic in the local network is not ssl encrypted.

The issue you are facing:

My collabora instanz is only working together with NC when I use local names or IP addresses.

When I am configuring NC and Collabore with public DNS Names I always got:

The Collabora instanz is reachable by name from the public Internet without any problem.

My question:
Has anybody a Running NC with an IPV6 Only public address together with collabora behind an nginx reverse proxy?

and the curl on https://collabora…eu/hosting/ is also responding on port 443? If you are on local and you use port 9980, do you change this port to 443 (or is this proxied again?).
If yes, can you try it without a proxy (not sure if collabora does https on its own)?

I have found the solution:

the problem is that the charts on truenas do not support ipv6 name resolution. But nextcloud.mydomain.com only has an ipv6 aaaa record. The result was that the collabora instance is not able to access files on nextcloud.mydomain.com.

The workaround for this is to use the kubernetes coredns pod to resolve the ipv4 addresses for these domains. after adding some lines in the coredns configmap with:

sudo k3s kubectl -n kube-system edit configmap coredns

updated the hosts entry the following lines:

        hosts /etc/coredns/NodeHosts {
          192.168.124.76   nextcloud.mydomain.com collabora.mydomain.com
          ttl 60
          reload 15s
          fallthrough
        }

the truenas apps are able to see each other using ipv4. The ip 192.168.124.76 is the address of my nginx reverse proxy manager instance.

I am happy to resolve this problem after at least 15 hours of work with an easy solution.