Not receiving authentication/verification code from SSA Benefits website.

I'm having the same issue receiving a short code from social security admin. - Its an authentication short code 79913. we confirmed no short code blocking is on the line. it works fine for one of our accounts/phone numbers, but not the other.  We've switched sim cards and confirmed the issue follows the phone number, meaning it isn't an issue with the phone itself.  So I'm thinking the issue has to be something with the sim card or behind the scenes at tmobile. The issue has been escalated at tmobile for over a week now so hopefully they'll resolve. I was curious if anyone else ever resolved this?  

the line is post paid and i’ve only noticed the issue with this one short code from SSA so far.