I went with the auth0 sign up flow , and registered as a user and then i got auto logged in to my website. After that i went to user management - > users to check the registered user.
Then i clicked the registered user and made the email as verified , after that i went to my website and refreshed the page the login session is getting expired and it is redirecting to auth0 login page to login again .
I have just tested the sign-up flow on my end and did not get the same results as you. Instead, when I signed up and changed the email verified status to “verified”, the login session remained intact.