Krileon,
We don't use the Joomla login module; we rely on the CB Login module and, yes, the Login is an item in the Main menu. I left Redirect URLs and Rewrite URLs enabled in the System-Community Builder plugin. I disabled Verify Consent, however. The CB Login works fine now and automatically redirects to the user's Profile, as it should.
Between us, I've found some aspects of the Joomla MFA Tool Suite problematic. Despite the inclusion of custom CB privacy consent fields displayed in the CB Registration form,the user responses are not recognized as Consent Requests in Users/Privacy/Requests or /Consents. Activation of the Joomla Content-Confirm Consent and System-Privacy Consent plugins results in throwing a System Message advising a logged-in user to specify Privacy Consent but, even if the Joomla Privacy plugins are published and appropriately configured (per the Privacy Status Admin module, provides no additional means to satisfy that advisory. I created a separate Privacy item in the Main Menu for users to click "Yes" or "No" (in addition to what the user answered in the CB Signup form), but clicking that link failed to remove the warning and failed to show the actual Consent form that should have appeared when the link is clicked.
Oh, well.
Again, thanks very much, Kyle.
Don White