Ensure you're using the CB Login Module and not Joomlas login module or any other login module. Next ensure your login redirect within your CB Login Module begins with index.php and is non-SEF. This should guarantee it always works. If you're using a relative SEF URL for the login redirect it could fail due to how URLs are rewritten in Joomla. Additionally ensure the first time login redirect within CB > Configuration > Registration is empty unless you want a different redirect for the first login.

If you can, it would be very helpful to be able to read in the popup information box where the redirect address is entered the need to use the index.php/address.

You don't have to provide non-SEF beginning with index.php, it's just more reliable. This is same behavior throughout all of Joomla when providing URLs in parameters; so something to keep in mind if you run into any other URL based parameters. Regardless we could certainly use some improvements on some of the parameter descriptions and have been gradually working through our products to improve all parameter descriptions.

Also, the need to leave the Configuration area redirect box empty. That is not obvious procedure to many of us.

It doesn't have to be left empty as that's the first login redirect. It only impacts the users first login and defaults to sending the user to the profile page on first login. With parameter description improvements in the future it would be good for the login redirect parameter in the CB Login Module to note about the first login redirect though.

Have created a feature ticket to keep track of parameter description improvement suggestions.

forge.joomlapolis.com/issues/7583