Hi @jdesrochers,
It is possible to get a refresh token is a SPA, but you would have to have misconfigured your app in the dashboard. If you were changing settings then that could explain why you were able to get one. It is hard to say why without any detailed information.
The prompt=none call is requesting a silent authentication, and that is the recommended flow for a SPA. I would suggest taking a look at our React quickstart if you are interested in best practices.
Hope this helps,
Dan