Doorbell Pro resets after a few minutes

i'm just trying to complete the set up for a ring doorbell pro and once the set up is complete, the light turns to a 'soft' white light and the doorbell seems to work OK, connects to the chime, captures video, but for 4 - 8 minutes and then returns to the start up mode - telling me its the most advanced doorbell etc and I have to set it all up again??? It doesnt feel like the most advanced doorbell in the world.... I've done the hard reset, rebooted the router, device health seems good, hardwired with a Ring plug in adaptor. It sounds like the wifi connection is dropping out but everything else in the home is working well, no record of any wifi drops. Download reading 44Mbps, upload 9Mbps, so fast enough....