PPPoE Connection Failing with Authentication Fail

Evening fellow forum members,

I am just setting up a new Sophos Firewall XG device (Version: 17.0.5 MR-6) and are having issues getting the WAN PPPoE connection working.

I configure WAN interface as PPPoE and enter my ISP Username and Password but when I try to connect I am getting "Authentication Fail. Please check Username & Password".  I am pretty confident the username and password are correct as I pulled them out of my Linksys WIFI router which connects fine so are not sure what to check next.

The obvious question is have I cabled correctly so yes I unplugged the CAT-5 cable running from the NBN box into the WAN interface on Linksys router and connected it into the WAN interface on my Firewall XG box.

When I try to connect this is what I see in the logs:

Port2 : PADI Packet sent from interface

Port2 : PADO Packet received from server

Port2 : PADR Packet sent

Port2 : Discovery Process Completed

Port2 : LCP Link Established

Port2: Authentication Fail.Please check Username & Password

So definitely appears that the username or password is incorrect but I am pretty confident they are correct as like I said I captured them from my Linksys router which connects fine.

One thing I found in searching is that some people said you need to activate the Firewall XG device before PPPoE can work.  Is this actually true and does it fit the symptom I am getting?

Any ideas of what to check next as I am out of ideas short of contacting my ISP to change the password just to 100% confirm I have the correct password.

Thank you in advance for your replies.

Jase.