Re start the phone, .also umplug Neo too to reset everything
Well I seem to have got it working again.
I tried to connect to Zwift on Apple TV, but Zwift couldn't see the Neo. Tried to connect to the MacBook, but same problem, although ANT+ was ok. Then I decided to try Bkool instead, but same problem - no connection via Bluetooth, but ANT+ ok.
Before trying all these combinations, I'd tried connecting to the Tacx utility on my iPhone. Initially, same problem, but after restarting the iPhone and the utility I managed to connect and the Neo seemed ok according to the utility.
After almost giving up, I had one more look at the Tacx website, which reminded me that Bluetooth is a 'closed' protocol that only connects to one application at a time. So, I went round and powered off everything that runs Bluetooth, the Apple TV, my iPhone and also a second Apple TV I have in the house.
Tried again to connect via Bluetooth on the MacBook and this time success. Disconnected from the MacBook and closed Zwift, then tried to connect via Apple TV and success again.
So, it seems that the Neo still thought it was connected to another device via Bluetooth. I'm not sure how it got into this loop. When I switched on this morning, I got a message on the Apple TV that the Neo had disconnected, which suggested it had connected at some point, but I'm still unsure what it thought it was connected to at that time.
Never mind, closing everything completely down seems to have got the Neo out of this particular loop and everything seems ok. Fingers crossed next time I go out to Zwift.
Oh and just to top off my day, Zwift decided I hadn't ridden the Cucumber workout session in the Build Me Up programme that I'm doing, even though I rode it this morning and its listed on My Zwift page and has downloaded to Strava. It was telling me it was my next workout ride, so I'd need to ride it again.
It nearly killed me. It was 90 minutes of hell, so I checked the option that allows you to tell Zwift manually that you have completed the workout. Cheeky bastard app then set a status that said I'd ridden it outside! I'm not doing that workout again!