Docker host mode & ipv6

I hope this post is in the right category, otherwise my apologies!

I am running a single-server Docker CE (19.03.4-3.el7.x86_64) instance on a CentOS 7 server with docker-compose (1.24.0, build 0aa59064). I have disabled docker firewall management to have better control over what is allowed and what not. Everything is working so far.

I’ve got a web service running (Nextcloud) and a nginx proxy container (link) I made myself, I run the nginx container in “host mode” to be able to pass the real IP correctly through the Nextcloud logging. I wanted my website to be able to be reachable on IPv6 as well but I noticed the ports (443/80) are only bound to 0.0.0.0:80 instead of :::80.

How can I make sure I can run my proxy container in network mode and have it also bind to my external IPv6?