Many thanks. When I transitioned from HUB1 to HUB2, I experienced 2 new problems that I had not had with the HUB1, namely eratically slow WiFi, and intermittent disconnections. I observed identical behaviour from the 3 HUB2s I experimented with (one extra purchased, and one supplied by TT). I tried separating the 2.4GHz and 5GHz SSIDs, setting the channels to 11 & 36, and connecting only to the 5GHz signal. This immediately solved the WiFi speed issue, and I now get the maximum speed for my package (75mb/s). Interestingly, I did not have to separate the SSIDs on my HUB1, which operated perfectly with the same 7 dual-band devices in the same locations, so I have concluded that the HUB2 has a problem communicating optimally with dual-band devices.
The second problem I have had with the HUB2 is that occasionally my Echo Dots report they are "having difficulty connecting to the internet". On the 5GHz band, Echo Dots can only connect on Channels 36-48, so if the router jumps temporarily to a higher channel they would loose connection. As the signal strength is good and I have no WiFi congestion issue, I am thinking WiFi Optimisation could possibly be the cause of the disconnection problem. I'll monitor for a week and report whether the intermittent connection problem has disappeared or not.
