Hi @planger,
When using api.redirect.sendUserTo() in a Post-Login, the user is redirected to the specified URL, and Auth0 does not cache it.
If the user is still being redirected to localhost, I recommend checking your network activity to verify the requests and check them against the Dashboard Logs. I would also check that the redirect_uri of your /authorize request does not point to localhost either.
It might also be helpful to include some console log statements in the Action scripts and monitor the output in the Action Logs during a login flow.
Let me know how this goes for you.
Thanks,
Rueben