For the past few releases not sure when but none of routines are working. Lights randomly turning on, upon checking i saw google triggering the alerts for lights so I removed it completely
Now I can't add google home devices it says can't add or at times gateway 504 error
Not sure what you mean by this ... What alerts, where?
Are you using Hubitat's built-in Google integration, or the community version?
Have you rebooted your router recently, that could result in your hub getting a different IP address if you don't have DHCP reservation for it in your router (preferred), or haven't set a fixed IP on the hub, which could cause problems.
Error says oauth. In google home add a device then works with google then find hubitat and re-enter your hubitat credentials. My integration got mad at me once and that's how I fixed it. Hope that works.