Why do we have no camera feed?

Our internet runs at around 400mbps and the Nanit Pro camera is around 4 metres from the router. For around 6 weeks, it worked well, and there was only temporary downtime for the camera. Over the last week, the camera has kept cutting out.

We have followed all the troubleshooting guidance: unplugged the camera, switched off the mains power, restarted the router, etc. On restart, it initially suggests the 'camera network signal' is High. However, after a few minutes, the 'camera network signal' shifts to Low, even though nothing has changed.