Cameras Offline

I have 5 2C cameras linked to a Homebase 2. The Homebase is connected to the router via ethernet. The system has worked flawlessly for four months. This week every camera went offline. Currently, only two of the closest ones work (albeit inconsistently) and the range seems limited to only about 20 feet or so. I’ve tried reboots, and reinstallations to no avail. I also tried different channels, which no improvement. Any suggestions?