Can not get RCON to connect to server

I'm new to docker and have managed to install a Creative and Survival server. I'm trying to RCON the Survival server, but connection is always refused.
I have enabled RCON in the server.properties file using port 25566 with rcon.port=25576
and RCON is starting successfully.

I am attempting to run this command from terminal to setup rcon-web:
docker run -d --name rcon-web -p 4326:4326 -p 4327:4327 -e RWA_PASSWORD=guipassword -e RWA_RCON_PASSWORD=minecraft -e RWA_RCON_PORT=25576 -e RWA_RCON_HOST=127.0.0.1 -e RWA_SERVER_NAME=mc2survival itzg/rcon

When checking the logs in portainer for rcon-web, I see:
2021-03-18T15:18:54.475Z RconServer [127.0.0.1:25576]: Connection failed

and error in the GUI of:
The current selected server is not available anymore. Maybe gone offline?

Can anybody help with this, I've spent a day on it! My Daughter needs op'ing and I'm getting it in the neck :-)
Thanks

Start with the posted docker run command and the rcon-web logs showing a failed connection to 127.0.0.1:25576. Check how the container reaches the Survival server and verify the configured RCON host and port; done means the GUI connects and the selected server is available.

Written by the indexing model from the issue text.