I cannot get sign into Apple to work with any user flow in Azure B2C. I am using the base interface on B2C and attempting to run a user flow. When I select Sign in with Apple in the flow it redirects to Apple and handles the sign in but when I hit continue it throws AADB2C90289 and fails.
So far I've gone through the set up for Apple sign in with Azure probably five times now. I've configured the app group, app service, signed the JWT key from Apple. I can test everything, run my secret through jwt.ms and it all looks fine.
I'm using https://appleid.apple.com/.well-known/openid-configuration as the metadata endpoint which seems fine. I tested the metadata with an Azure function and it was ultimately the same result. If I turn off the Azure function then I can see a relevant error. So I know that is not the issue.
I've followed this guide so many times that I can do the whole process without thinking about it. https://github.com/azure-ad-b2c/samples/tree/master/policies/sign-in-with-apple
Microsoft support has been unable to assist as the most they've done to help was to show me logs with no real information and ask if I'd used the link above.