Wyze Cam Floodlight - Sound not working (listen, not microphone)

We have 2 of these, one the sound works fine on one. On the newer of the two, the sound worked fine when we first installed it, now it does not work at all. Restarted camera, no joy. Only tried iOS app, that’s all we have, 2 iPhones and an iPad, no sound on any of them.