I have a Nest Secure System and a Nest x Yale Lock.
I can arm/disarm and lock/unlock the respective devices from the app on my Samsung S22 Ultra. I have the Home/Away Assist turned on. I receive notifications asking me if I want to arm/disarm or lock/unlock on both my phone and my Galaxy Watch 4. Responding to the notifications results in a message that the system could not be armed/disarmed, or locked/unlocked. If I go into the Nest App, I can do either operation without a problem but this is far more cumbersome than just clicking "Set Alarm" on my watch or phone notification.
Are there permissions or something else that needs to be configured?
I am terribly sorry to hear that you're having this issue! I would love to assist you with this issue. If you are having issues with your Nest Cam or Nest Doorbell, I would suggest that you first start by restarting it.
Restart: Keeps all your settings, and it should reconnect to the same Wi-Fi network. This is helpful if it ever becomes frozen, has trouble reconnecting to the internet, or isn't working normally.