SeaFile 8.0.4 - Seafdav not working?

Hi,
I trying to activate seafdav on dockerized seafile server 8.0.4.

My seafdav.conf
[WEBDAV]
enable = true
port = 8080
fastcgi = false
share_name = /seafdav

I got “502 Bad Gateway” when I try to connect to “https://my.server/seafdav/

The nginx log keeps laughing at me with errors
2021/05/12 12:09:51 [error] 38#38: *4 connect() failed (111: Connection refused) while connecting to upstream, client: 172.18.0.2, server: seafile.my.server, request: “GET /seafdav/ HTTP/1.1”, upstream: “http://127.0.0.1:8080/seafdav/”, host: “seafile.my.server”

Inside the seafile container
netstat -an
does not show port 8080 on LISTEN state, what’s going wrong ?