Auth0 with Capacitor and Ionic 5

Hi All,

My first post here and a particularly tricky one from what I can figure out.

Basically I have a new Ionic 5 app, using the auth0/auth0-angular library in order to perform authorisation,
Now this works absolutely fine on web.
The issue comes on mobile build of the ionic app.
We are using Capacitor to do this.
The app loads, opens safari displaying the login page. It is important to point out here that this is the safari app itself, not an in-app browser.
I successfully login and I am presented with the popup (Open in AppName)
I click Open and am directed back to the application.
At this point however my app just freezes on a black screen.
The callback and redirect don’t seem to happen at all.
My iOS logs just say APP ACTIVE.

Been at a loss for about a week now.
Any help or bright ideas would be wonderful.

Thanks