I am having similar issue. Nest Doorbell (worked) started acting up (stuttered on and then offline throughout the day) a couple days go and then yesterday it just went off line. I tried all the usual troubleshooting but no luck. I'm quite tech savvy so know my way round. I tried the restart option with the pin, nothing changed, tried resetting the doorbell and removed it from the nest app but I found that I never get yellow circle etc after its supposed to be reset - I have a feeling it isn't. Now I just can't reconnect the doorbell to the app. The doorbell shows a blue ring every ten seconds and then goes off...over and over again. When I launch the app to reconnect the doorbell by entering the code it does find/see the last 4 digits of the serial number so the app CAN see the doorbell but it eventually fails with the typical NC022 Bluetooth error. I spent the whole day yesterday on it. I went as far as recabling the doorbell (just in case) but same issue. I brought the doorbell in and plugged to usb and tried the usual troubleshooting and get same error. I've a lot of Google devices in my house and I moved some of the devices next to the doorbell with the hope that Product Assisting would help. It says that it is using other nest products to help with the setup then moves to connecting to the camera and then eventually gets the NC022 error.
I'm using Google Wi-fi so last night I removed Google WiFi from the house and reverted back to the old router and renamed it so a different SID and just connected my mobile and tablet to it. (So no other Google/nest products were connected). I tired to add the doorbell via the app and I get the Product Assisting error saying that it was unable to find/access information from Google products so doesn't this show that the power/cabling is fine and the doorbell itself is probably fine too and that the phone CAN connect to the phone like it should? I reconnected one of my Nest cams to the new router and tried it again and I end up getting past the product assistating and then usual NC022 Bluetooth error again! Doesn't this show that it's not a WiFi issue? I've since reversed everything and back on the Google WiFi so my smart home can act as normal. After leaving the doorbell alone over night I gave it a try to add to the app and again I get same error nc022. I've tried several different phones and tablets, androids and apple phones and tablets etc and all same issue. I've uninstalled and reinstalled the Nest App and same issue.
From what I can sense from all the troubleshooting is that the factory resetting ISNT working and yes I have tried it dozens and dozens of times in all various ways eg inserting pin then pressing button, press button then insert pin, do both at the same time etc etc a d have done all with various times eg 10nseconds, 20 seconds 30 seconds...so long my fingers were sore!. I don't get the usual factory reset rings or dings etc at all like I've had to do before a long time ago. The reason I say this is that after seeing some of the errors eg the one when Product Assisting attempts to assist, when no devices found it stops and when there are devices available then it goes to the next step and tries to connect but ultimately fails, usually with the Bluetooth error but sometimes (I can't remember the code) but it meant that a previous doorbell information was found in the nest home. I feel that the Nest App/Google or the devices in the system think there is still has the doorbell information in it somewhere which is preventing me re-adding the doorbell back to the app. I think if the factory reset worked correctly then it should fix it or if Google can somehow tell me how to clear the memory of the doorbell from my nest home and NO I am not deleting my Google home and reinstalling (although this may work), I have too many devices in the house.
Any secret way of resetting the doorbell which isn't typically known??? Any ideas would be greatly appreciated.
