Nextcloud not accessible after reset of Truenas Scale

Hi, we’re running Nextcloud from Truenas Scale, installed via the regular official install tool.
Sadly, i had a reset of the server. I got every data pool running again and also the application window shows me a running instance of nextcloud. Yet, i can’t access it.

I guess the the port for nextcloud (:9001) is not open anymore. What would be the best way
a) to check, if that is the issue
b) to reactivate that port

I have a similar post at the Truenas Community, but without any further reply so far. So i thought, maybe I get a better help here.

Thanks in advance!