I’ve been reading up on the Authorisation Code Grant flow at Call Your API Using the Authorization Code Flow, and as far as I can tell the problem is that there is no id_token in the Access Token exchange.
As I’m using the default hosted login page, the only place I can think of to tweak is my /authorize URL, which is currently https://mytenant.eu.auth0.com/authorize?client_id=abc123&response_type=code&redirect_uri=http://mydomain.com/index.php?auth0=1. I’ve tried adding &audience=https://mytenant.eu.auth0.com/api/v2/ as well, but no change