@nicolas.garcia I’m running into the same issue as @vamashraddharsh . Here’s the error page which gets embedded in the URL hash after the login flow completes:
Update: I suspect that the login_hint is not being passed to Shopify when Auth0 tries to fetch the user profile. After reading this Shopify forum thread I suspect that the association with the shop may be lost after the first redirect.
Oddly, the HTML response is being sent from Auth0! It must be proxying the error code from Shopify. This all happens before control even returns to my application, so the bug does not seem to be within my control to fix.