Setting up CORS for Google Sign-in fails for mobile browser?

I authorized my website as an origin for my webapp's Google Sign-in service in GCP. Sign-in works for desktop browser, but the mobile browser fails with the following error:

PlatformException(idpiframe_initialization_failed, Not a valid origin for the client: https://[redacted].app has not been registered for client ID [redacted].apps.googleusercontent.com. Please go to https://console.developers.google.com/ and register this origin for your project's client ID., https://developers.google.com/identity/sign-in/web/reference#error_codes, null)

Any ideas how to fix this?