What firmware is your C8 and plugs on? For my KASA's, I'm on firmware 1.1.4 Build 231019 Rel. 174214.
You definitely want to go Google Home to Hubitat and add to the manufacture's app last. What Google Home device are you using? You might need to unplug everything and force close the app on your phone.
As a temporary measure, you can get them into Hubitat via a non-matter integration ([RELEASE] TP-LINK TAPO Plug, Switch, Bulb, Hub and Robovac Integration).
