When using the option to validate logins on Connect for Chromebook setups, the validation page no longer shows any buttons on the validation page.
Due to the depreciation of Google+, the validation features no longer work as expected. Smoothwall is working on reinstating the functionality.
To authorize and authenticate users normally, set the SSL login page as a startup page in the G Suite admin console. Once done, the connect client can authenticate normally.
NOTE: If G Suite logins aren't needed on the SSL login page because only Connect for Chromebooks uses Google logins, you can turn off the validate option. You only need the option when users need to use the login page to authenticate using Google accounts. The Connect for Chromebook clients can authenticate correctly without the validate option turned on.