While looking for setup info for new poster I found errors. This guide has somehow managed to show an image of an ONT for instead of a master socket for both types of master in step one. So a DSL customer is told to connect the DSL cable or micro filter to the "primary socket", but is shown an image of an ONT instead.
https://www.bt.com/help/broadband/getting-set-up/how-to-set-up/bt-smart-hub-2
Given that we tell primary school children to check their work before submitting it, I despair...
Thanks for taking the time to report this to me @rbz5416.
I will get this reported back for you and hopefully get it changed soon.
Thank you
DanielS