Doorbell3 offline issues

We have a doorbell3 (10 months old) that before the 27th December 2022 was working well and had no known issues. Then from the 27th December 2022 we have been regularly seeing it offline and not available to be used.We have not changed ISP, moved the router or changed the router.It is mounted on an an external brick wall.We have no new electrical devices in the house.We also have a ring camera mounted on the same external wall approx 2m above the doorbell and this does not loose connection, ever.I have powered off the router for both 30secs and 1hr and neither fixes it.I have used different iOS devices via the respective apps to reconnect the doorbell and this does not fix it. I do not have an android device to try.I have taken the battery out for 30secs and also for over 1hr and neither fixes it.I have tried resetting the doorbell (press and hold orange button for 20seconds) this does not guarantee finding a Wi-Fi signal afterwards.I have tried to use a Wi-Fi range extender to boost the Wi-Fi and this is not fixing it either. I cannot put a Wi-Fi extender between the router and the doorbell as there is no power socket to do this.No other wirelesss devices in the house has issues with the Wi-Fi.Standing next to the doorbell with my phone I can multiple wifi but the doorbell sees nothing!I called the tech support line earlier and it managed to reconnect to a Wi-Fi signal (I had been trying to reconnect for 1hr prior to the call being placed), then lost it 10 minutes after the call!Can someone help?