Hello,
I’m sorry to use google translate, but I’m from Czech. 
Is there any special setting for NC 10 when using a router microtik?
On the internal network everything ok, out of the network only data - can be read, shared, …
IP address is public
NC 10 constantly reports that it has no internet connection, can not use notes, task, …
Thank you for shifting
Sounds like problem in basic network interface settings, usual suspects DNS & Firewalls or Proxies. Without further information hard to guess.
It looks like a firewall.
Proxy - we do not
Change DNS to google 8.8.8.8 - no change
We redirected ports 80 and 443, but notes, task, … are not running on another port.
Or, do not need to redirect other ports to NC?
So yesterday we checked the microchip router and without success.
Nextcloud 10.0.3 runs on Freenas 9.10. And constantly shows this message:
This server has no working Internet connection. This means that some of the features like installing external storage, notifying updates or installing third-party apps will not work. Accessing files remotely and sending notification emails may not work, either. We recommend that you enable Internet connection for this server if you want to have all the features.
External storage does not work, external applications (notes, task) do not work.
Notes and external storage works only on the internal network - tested.