Help! Nextcloud Jail suddenly not reachable, truenas.local is also not resolvable

[BdmRt]

Hi,
I am new here and could not find an answer to this. I managed configuring and installing everything, today I wanted to sync my cloud data to Nextcloud jail. It worked fine till suddenly during Photo Sync of my smartphone it stopped. I tried reaching TrueNAS.local or my DNS to reach my Nextcloud, both not possible anymore, out of nothing.
I restarted the nas also, but did not change a thing. Any ideas what could be the issue?
Im concerned about the system if this can happen just after a day without a reason, I expected it to be rock solid..

 

[BdmRt]

Forgot to mention, I can reach the nas over IP. But the Nextcloud page not

 

[BdmRt]

Well, I could not stop trying and searching. I ended up diagnosing that nginx could not make a proper forward because of already bound ports. I could not manage to solve the nat solution I used, so I ended up using a new static IP for my jail. I had to make adjustments in the config files, as well as change the forwarding in my router. Just saying if anybody else could have