The carrier level issues affecting T-Mobile are now confirmed to be fully resolved.
Duo is seeing success with SMS message delivery to T-Mobile subscribers but continue to see issues with phone callback authentication to T-Mobile numbers.
Duo has identified this as a carrier level issue affecting T-Mobile. They are working with their partners and the carrier to resolve this as quickly as possible.
Duo has identified issue with Phone Call and SMS deliveries to T-Mobile phone numbers on all of our deployments and are working to correct the issue as soon as possible.