Encountered the same issue, wasted few hours debugging so leaving the answer in case someone else will have this problem as well. The root cause and solution here: Losing login credentials on refresh using @auth0/auth0-spa-js - #10 by mathiasconradt
Basically, don’t use an account created with Google Social Login (create a user in regular database connection) or don’t use Auth0 dev keys for the Google social connection.