Access Tokens from Entra External IDare incorrectly issued from v1 endpoint (sts.windows.net)

I followed along with Entra Id SPA tutorial on Microsoft Learn, and created a new App Registration in my new Azure Entra External tenant. I can verify that in the app registration manifest that the v2 endpoint is specified by the "requestedAccessTokenVersion": 2. The ID tokens issued by my Entra External tenant are from the v2 endpoint ("https://<my-tenant-id.ciamlogin.com/<my-tenant-id>/v2.0"), but the access tokens generated are from the v1 Issuer ("https://sts.windows.net/<my-tenant-id>/").

How can I get Entra to issue access tokens from the v2 endpoint?