Thank you for bringing up the concern you're experiencing, I would love to look into this further for you. The first troubleshooting step that I'd recommend would be to restart your device. This process should keep all your settings, and reconnect it to the same Wi-Fi network. This is helpful if it ever freezes, has connection problems, or isn't working normally.
I'm dropping by to ensure that everything is covered here. How's it going with your Nest Camera? Aside from restarting your Nest Camera, try restarting your Wi-Fi network and your mobile phone. In case you're still getting the same issue, try resetting it to the factory default. Remember that after the reset, all of your recorded events will get removed as well. Let us know how it goes.