Doorbell Pro Stopped Working again

My wired Doorbell Pro stopped working (went "offline") after 11 months of working correctly. There were no changes to my network to cause this. I spent about 90 minutes on the phone with tech support and tried everything, but we could not bring it back. Reluctantly, I bought another one (I had to buy it because I waited until after the 12 month limit to call it in).Installation of the new one went smoothly and it worked perfectly for about two hours, then it went offline too.I've spent another two hours with tech support and did everything, including a hard re-boot and removing power. Ring tech support told me they would re-flash the embedded sw and re-build the application overnight and "guaranteed" that it would work in the morning. It did not. Clearly, Ring Tech Support doesn't know what to do to get me back on-line.On my own, I've also re-booted my network and phone and then re-booted the doorbell. Still nothing. In all cases the doorbell light pulses but doesn't "spin". It gets to the point of trying to connect to the Ring network but can't. My mesh network sees the doorbell as a connected device. Ideas?Separately, this is my third Ring doorbell in three years. The last one lasted only 11 months - they are very unreliable.