You should have never lost support on 14.3. Download 14.4 and it should work again. If it doesn’t, try unplugging the Connect:Amp from power for a couple of minutes and reboot your router and phone.
I suspect, although I don’t have one myself, that support wasn’t dropped….or at the least, shouldn’t have been. There may be another issue, either in your network, or with that specific device, but it’s hard to tell.
You’re much more likely to get more assistance if you call Sonos Support directly to discuss it.
When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.
I’ll put it down to a bug in 14.3 as it’s back to working in 14.4. Whew.
and thanks for the quick replies :)