Sign-in success rates are back to normal. Resolved. API key authentication was never affected, so server-to-server integrations continued working throughout.

The rollback is complete. New sign-ins are working normally. Merchants who were affected should sign in once more to receive a valid session.

A change to token refresh handling released this morning invalidated refresh tokens issued before the deploy. We are rolling the change back.

Merchants are reporting that they are signed out of the portal shortly after signing in. We are investigating.