@island17,
I don't see any reports of cloud issues on our end, but I will check again in the morning for any cloud status updates.
Ensure that in the list of connected accounts, you do not have your Kasa account already linked. It may be possible that the connection errored the first time and is attempting to use invalid credentials still.
I would also recommend uninstalling and reinstalling both the Kasa and Google Home Apps, specifically the Google Home App. As a result of the updates to the Google Home platform bringing matter support, there have been quite a few updates from Google. In my own personal case, my Google Home apparently did not install correctly and caused issues adding devices to Google Home.
You may also try creating the connection on another phone or device to determine if it is your installation that is failing the setup or if it is something from the backend systems throwing the error.
If you have been continually testing and trying, please also wait a short while before attempting again, as your account may have sent too many requests over a short period to the server. While I do not know if there is a protection such as this, its relatively common for timeouts to be assigned for repeat requests to an API.
Can you provide what version of the Google Home App, Kasa App, and Phone you are using to set up the device?
Please make sure that you are also connecting the same TP-Link ID that is listed in your Kasa App. Far too many times I have seen the wrong email being used to make the connection.