All of your cameras need to be in the same "home" in the Google Home app ("structure" in the Google Nest app) as your Nest Aware subscription in order to be included in your Nest Aware subscription.
If you go to Settings in the Google Home app or Google Nest app and select "Nest Aware", it should tell you what subscription you have. If you select Settings for a camera in either app and select "Nest Aware", it should also show what Nest Aware subscription you have. If both of your cameras are in the same "home" or "structure", your subscription should show.
You can check your Nest Aware subscription here: https://store.google.com/subscriptions?hl=en-US
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