This is a problem with the integration communications between Google and Geeni. I have a couple Geeni smart switches still on the Geeni app that are working with Google home but there are several times every month that assistant will give a reply "Unable to reach Geeni"
Most of my Geeni smart switches and the one light I have I have installed using the Tuya Smart app and these never have any issues. When I get around to it, I'll move the remaining two off of Geeni onto Tuya and then get rid of the Geeni app and integration. If you want to go this route, when setting up your Geeni devices in the Tuya Smart app, you have to use the manual setup not the automatic one.
