Receiving user already exists for a user that doesn’t

Can you please try the following to debug the issue:

  • Add console.log(); statements inside your Create script in your custom database connection settings; I suggest adding them before each callback call.
  • Monitor the logs using the Realtime Webtask Logs extension
  • Perform a signup using a non-existent email address in your custom db
  • See which console.log statements were executed in your script.