when mapping a port to the host it is possible to bind it to a host/ip too.

# docker run --name test -p 127.0.1.1:80:80 ...

# docker port test
80/tcp -> 127.0.1.1:80

When building a docker rule now in plesk the host/ip is ignored and the proxy_pass goes for the default ip 0.0.0.0:

proxy_pass http://0.0.0.0:80;

The rule should respect the host/ip.

proxy_pass http://127.0.1.1:80;

Have a nice day
Felix