Update. Today I took the bold and stupid step of attempting to fix this problem. I work in IT and troubleshoot problems for a living, so I do loathe it when I feel I’m being beaten by a tech problem.
I took a pointy thing and reset my Naim Qb 2 and this time it caused a lot less aggravation than the previous occasion. However, it actually made my situation worse. First, the reset did not take back to factory settings but once more to the 4.4.0 firmware. This almost certainly is the reason for why I’m here now and what has broken Chromecast.
The setting up of network connection is at best a clunky and frustrating experience but after a few attempts I connected to my WiFi to discover that now my Google Home app doesn’t display the Naim at all. At least before it was there in some sort of broken way, but now nothing shown whatsoever. Checking my app and the system settings there is the Input section where all the audio connection options are listed. All are turned on and available to turn off if you choose to. All but one, which is the Chromecast option that is off and cannot be turned on.
So, I have dug out one of my Chromecast Audio pucks that are one of the finest things Google ever created and should have never stopped making and connected this to my Naim’s analogue connection. Now I have a working Naim casting speaker that is in my Home app and I can do all sorts of lovely things like play music.
My Google Home is still showing in some places the Naim Chromecast as an option to cast to but Spotify, Audible, BBC Sounds etc see nothing.
For anyone who is not experiencing Chromecast problems is I would say you have not updated the firmware in the Focal & Naim app and I strongly recommend you don’t if you value your Naim casting.