When the mesh was installed the tech should have made the SSID ( wifi name you'll see when connecting device ) and password identical to what was there previously. The devices would have reconnected.
Do now what you'll want to do is delete devices off your account. Go to the cameras and pull the power wait a few seconds and let them power back on. Try reinstalling them and if that doesn't work you'll need to factory reset the camera by using the power brick and usb cable the camera came with. Wait until the camera boots all the way up. Then hold the button in on the back of camera until you hear the chime. After they allow them to reboot fully then learn the camera in.
Remember: when you are first learning the camera in you'll need to be close to the camera. The camera first connects to your phones Bluetooth. Once your logged into your home wifi. You're safe to walk away to finish learn in process.
