Thanks Richard,
I will try, the problem is that this does not happen very often, its only happened 2wice in the last Month. I am busy doing dev against the API so logging in a couple of times every day. Also worth noting is that is only seems to have started when I upgraded to auth0.min.js v9.2.2. I hear you point about the end point possibly being incorrect however, it work 99.9% of the time. But There def seems to be some edge case that is causing the Opaque token to be returned and not the JWT. I will try to get the HAR but I cannot predict when its going to do this again.