Welcome to the Auth0 Community!
Thank you for posting your question, to ensure that your connection is OIDC-conformant please make sure to follow our documentation regarding creating the custom connection → https://auth0.com/docs/authenticate/identity-providers/enterprise-identity-providers/oidc#set-up-your-app-in-the-openid-connect-identity-provider. Otherwise to meet the OIDC standard you need to make sure that your connection matches the OIDC specification, there’s also an official document defines the set of profiles of the OpenID Connect specifications used for certifying implementations conforming to those profiles.
→ https://openid.net/wordpress-content/uploads/2018/06/OpenID-Connect-Conformance-Profiles.pdf
Thanks!
Dawid