We currently have both Production and Non-Production Foundation sites for use with Studio. When I originally logged into Studio, it was to the Production Foundation site. I now want to go to the Non-Production site but I am not prompted with the option. How can I switch from Production to Non-Production?
In the Account section, you should see a button that says Reset Activation. It will log you out of Studio but then you can select Foundation again and pick the site you want to use.
Refer to Changing your Foundation site