NGINX errors

Configuration
1

Suddenly I can not access my home assistant using my https://mydomain.duckdns.org address.
Everything only works locally using the local IP.
I restarted my raspberry several times but without success.
In the NGINX log I found this error repeated several times:

[error] 19 # 19: * 32 connect () failed (111: Connection refused) while connecting to upstream, client: :: ffff: 192.168.0.1, server: mydomain.duckdns.org, request: "GET / api / websocket HTTP / 1.1 ", upstream:" http://172.30.32.1:8123/api/websocket ", host:" vpomax.duckdns.org "

I use Hassio with HA v. 0.83.2
DuckDNS v. 1.5
NGNX v. 2

2

I uninstalled and reinstalled NGNIX … now it do not show the errors above but my external address mydomain.duckdns.org do not works…

403: Forbidden

3

After a lot of time… it works again… probably a Duckdns or Network problem… then after reboot it do not works again…