I installed the three discs, one on each of three floors of my house. Surprised connection on 2nd floor showing 'poor' Amber LED. Made me wonder: Does the 2nd and 3rd disc connect exclusively to the 1st? If so this is a star topography not a mesh as I was hoping for.
It may be better to change the subject of your post to "BT Whole Home Wifi - connection issues" as it will make it easier for people with that product to help.
There are quite a few existing thread on this forum, about this product, which you may like to read.
I have replied with a different subject header, as it may help to direct people to your question.
BT don't yet, and perhaps never will, divulge the technologies and standards that go into the Whole Home WiFi so it's difficult to say. If it's a mesh an AP should connect and route via the strongest WiFi 'backhaul' signal. This is likely to be the disc that is physically nearest i.e., the 2nd disc, but it could be that the environment in which the discs are installed is such that the signal between the 1st and 3rd disc is strongest.
I guess one way to determine whether the 3rd disc is connecting via the 2nd or directly to the 1st is to turn off the 2nd disc and see if the signal remains the same or gets worse.
Should the discs have a STATIC IP or DHCP?
If STATIC then do I need to set that on my HH6 as my HH6 is handling IP addresses? Not on the discs itself i presume (tho possible via manual IP in settings) as this may give a conflict or not??
I dont think it is meant to matter too much if they have a static IP or not, but I would be inclined to keep them as static to avoid the need for changing IP addresses, particularly if you are using with the Smart Hub as the DHCP is a bit hit and miss.
Presumably you have your main router Wifi disabled as this might be causing signal degradation and interfering with the WHWifi
I believe they are mesh, and the farthest disc should connect to the closest disc to it but from what you are saying this does not appear to be happening. It maybe that they settle down and establish the best connection if you give them some time?