@AP6
If you have the older Google Nest Hello Doorbell, then the internal battery in your Nest Hello (yes, there is one) may be failing, as it has for MANY other customers. It's failed on all three of our Nest Hellos. The chief symptom is that the doorbell goes offline for a minute whenever the doorbell button is pushed. It seems to fail after a year or two, sometimes more. Google Nest says they "cannot" replace the doorbell if it is past the 1-year warranty.
The workaround is to turn off the "Indoor chime" option, in which case your indoor doorbell chime no longer works, but the doorbell no longer goes offline. You can instead turn on "Visitor announcements" and rely on notifications sent to your Nest Hubs, Nest Minis, or Nest speakers (https://support.google.com/googlenest/answer/7672451?hl=en).
A few customers have pried open their Nest Hello and replaced the internal battery (https://www.ifixit.com/Guide/Nest+Hello+Battery+Replacement/131729).
This thread below on the problem has over 1,000 replies; if you want to understand the issue in detail, browse through the replies:
https://www.googlenestcommunity.com/t5/Cameras-and-Doorbells/Nest-Hello-Doorbell-cuts-out-when-butto...
