Default Can no longer send/receive SMS on T-Mobile

Suddenly I can not send or receive text messages (SMS). I can send/receive MMS just fine. When I try to send an SMS it sits in "Sending" then eventually it times out and asks for me to retry (which also fails).

I checked the SMSC and it matched what T-Mobile said it should be.

I am getting this issue with Hangouts as well as the stock Messaging app.

I can also make/receive calls no problem, nor do I have problems browsing the web on LTE.

Any ideas?