2x 2016 Vizio Chromecast TVs that both lose their connection to Orbi RBK50

Since install, both Vizio Chromecast TVs lose their connection between TV watching sessions.

Toggling the TV on/off/on using a remote or unplugging the TV and plugging it back in allow it to reconnect, but then it will lose it's connection again within a few hours. 

The trouble is that I did a firmware update when I connected the TVs to my new Orbi. Everything else on the new network are working much much better.

Any suggestions for a troubleshooting process to get this issue nailed down and fixed?

Thanks!

Erik