Hi everyone i experienced the same problem but with an exiting background:
On a Cloudron that was spinned up at Feb 2021 NextCloud talk Calls from outside the local network doesn't work: Not connecting calls.
We just spinned up another Cloudron for another Team with the same configuration and the Nextcloud Talk Calls ran out of the box!
I don't want to attach another Service/Backend and i also don't want to "customize" the Firewall settings, but i would love to have a running NextCloud talk System on the older Cloudron too.
Maybe the Cloudron installation script changed in the last years so that it works now but not before..!?
Does it make sense or does anyone have an idea how to apply the same settings to the old cloudron?
I could maybe provide some infos of both instances. Maybe comparing the iptables settings would make sense?! I'm not a server-expert so a little help here would be much appreciated! Thanks!