When logging into Zendesk Sell using SSO, if you accidentally select the wrong Google account, you get stuck in a loop of not being able to log in. Even if you go back and select the correct SSO account, it takes you to the page to type in your email address and then says the email address is not found. If you click to login with SSO and select the correct account, it still takes you to the page where you have to type in your email, which isn't found.

The only way I was able to fix it was to go over to our Zendesk help center / support ticketing portal and sign out of my personal Gmail there. Only then could I go back to Zendesk Sell and successfully log in with the correct SSO account. This isn't a route that most Sell users would have or think about using, so many would simply be stuck until they restarted their browser or cleared browser history.