Unable to connect to SQL Server container when on home wi-fi

I am quite new to the Docker world.

I am running Docker for Windows.
Version 18.03.0-ce-win59 (16762)
Channel: stable

My OS version is Win 10 Enterprise Version 10.0.16299 Build 16299 64 bit.

I am running a SQL Server container. https://hub.docker.com/r/microsoft/mssql-server-windows-developer/

docker run -d -p 1433:1433 -e sa_password=test1 -e ACCEPT_EULA=Y microsoft/mssql-server-windows-developer

I follow this blog https://blogs.technet.microsoft.com/dataplatforminsider/2016/10/13/sql-server-2016-express-edition-in-windows-containers/
and try to connect to the SQl Server container from SSMS(Sqlserver Management Studio) running on the host. For this i run the docker inspect, capture the IP for the container and plug it into the SSMS.

I am often on the move and when i have my 4G internet dongle connected on my laptop, this works fine. I am able to connect to the container from the host.
When i am at home , i hook onto the home wi-fi. I capture the IP from docker inspect but this time,connecting to the container from SSMS running on my host fails.

What i noticed is, when i am on home wi-fi, and i run tracert ,it goes out to the ISP and says can’t recognise IP. it doesn’t seem to recognise that the IP is within the local machine.
But, running tracert when i have my 4G dongle on, works fine.

Please can anyone suggest a solution.