@rez I see. Cloudron apps do not run in host mode because we need the network isolation for security purposes. Still I am not sure I understand why a docker container cannot access external network regardless. I thought this was taken care of by linux routing.
You were right. "unbound" was failed. Turns out IPV6 was disabled which was causing "unbound" to fail and in turn causing the issues with resolving domain names in Nextcloud. This is a vanilla install of Ubuntu 16 LTS so I'm not sure what happened. I enabled IPV6 and rebooted and everything started working. Thanks for the tip.
