Google doorbell and camera won't connect

Have had our network up and running for 9 months in our new home. No issues. In the middle of the night 2 nights ago my two Google battery doorbells and 1 Google outdoor plugged in camera disconnected from the network. All other Google devices and non Google devices work fine. 

Was on with tech support with Google for hours yesterday. Factory reset the devices and they will not connect to our WiFi. I've tried everything but every time I get to the step to connect to our WiFi they won't connect. Here's the kicker - they connect fine to the mobile hotspot on my Xfinity phone that connected to our WiFi. They connect fine to a neighbor's network. I've tried everything (rebooting our modem many times) but can't figure it out. Why would they be fine for 9 months than all disconnect from WiFi at the same time and can't get back?

Really looking for help.