Hi @truescope,
After looking at the docs I found some display options that might help with this:
https://auth0.github.io/auth0-spa-js/interfaces/gettokenwithpopupoptions.html
I haven’t tried it, so I cannot confirm. But it may be worth investigating.
Just to confirm about your setup, are you accessing the SPA on a mobile browser like Chrome or Safari?
Let me know.
Thanks,
Dan