Wireless Doorbell (2nd gen) rings on its own, coincides with health checks.

Twice now my ring doorbell (wireless, 2nd gen) has rung on its own. I'm not talking about motion notifications, I'm talking about actual ringing ( a missed ring notification in events), as if someone pressed the button. No other motion is detected, and in each case (04:32am and 10:21am) it shows a health check under the device settings for the same time. This is obviously becoming a bit annoying, especially the early morning one, as it sets my dogs off barking. I've had my doorbell since April this year and this is the first time it's doing it. I've trawled through the other forums, and most of them are related to the wired doorbell and possible wires crossing or shorting. Nothing like that in my case. Any help would be appreciated.