Problems connecting with nginx | Seerr | Page 1

Hi all, apologies in case the title doesn;t make sense. But I was able to use the overseerr app on my iphone by creating an icon with the url link and all was good. Since I moved my whole plex system and dockers etc from my Mac Mini to Qnap I have been unable to get things working as they were.
Plex works fine as well as Sonarr and Radarr etc
Nginx is working
Overseer is not. I have nginx linked to my domain name and the destination is the http://ip.address:port and lets encrypt is working (as it was before) - but since the move it is not.
I have everything running as a dockers in container station.
This is what happens when I click on the domain name in safari - The web address bar changes to my domain name for about 2 seconds and then it changes to the ipaddress of my qnap and just hangs there - trying to connect I'd say. Eventually it comes up with
504 Gateway Timeout
Any ideas ?

#Problems connecting with nginx