This might help?
Not sure if this is part of the issue or not, but I did select in the Security Assist to use the PowerCMS Users and the two users that I do have don't meet the user name/password requirements of Security Assist (they do/did work fine for the PowerCMS). So when I try to login to the Protected page using my users created or PowerCMS, they don't meet the required length/etc.
This might be a further issue or shed light onto the current issue...not sure. Your help is greatly appreciated!
(PS: for this purpose I am not too worried about not having the Live Edit for the Protected Page, the other pages it would be great to have it, but not super worried about it, if that helps!).