Bt whole home

[TechIgnoramus]

Hi.  I have a bt whole home set up (3 white discs) which I connect to a router which gets mobile broadband.  It works very well, but now I need to connect another disc, which is proving difficult.  I don’t seem to be able to connect to the BT app to add the disc

And connecting the new disc to the router until the light turns solid blue and then disconnecting it  (which is what I used to do) does not work either.  
Can anyone suggest anything ?  The disc (which I had to buy refurbished second hand from Amazon) seems to be working fine.

thanks in advance 

[Keith_Beddoe]

@TechIgnoramus 

Welcome to this user forum for BT Retail phone and broadband customers.

It would be best to give the WHW product helpdesk a call on 0808 100 6116 ( Mon to Fri 9am to 5.30pm and Sat 9am to 2pm) or drop them an email to: btconnectedhome@bt.com and they'll be happy to help.