Apps behind nginx not reachable any more

I have the set-up below on my TrueNAS box. Everything was working fine for some time.

Something changed and I am not able anymore to reach my apps through nginx.

I can open the apps through the truenas ip and port.

Any idea where to start looking how to fix this?

Versions:

TrueNAS 25.10.0.1 - Goldeye

nginx-proxy-manager App Version: 2.13.5 / Version: 1.2.23

“solved” I guess. Reason was my ISP who changed from dynamic IP to carrier grade NAT … so different problem to solve