Hey there @isafranco13 , thank you for posting! 
Let me please replay generically, providing known-to-me scenarios so you can possibly find an analogy to your stack.
Generally speaking, the sign-in after sign-up is required only if specifically set this way.
With the Auth0-hosted Universal Login page, a user should be automatically logged in after the sign-up by default.
With the customer-hosted Login page implementing the Auth0’s Lock library, configuring Lock with the option loginAfterSignUp:true should ensure the behavior.
Another scenario is when you are registering a user from your backend. Then you could log the user in via the Resource Owner Password grant and get the user tokens.
Also, it could be a good idea to review if there are Action scripts in your Auth0 tenant that may result in requiring the login after the signup.
Hope this helps! Happy to open the topic to a broader audience as well!