Unable to receive texts from 5 digit short codes

Hi all! I just switched to T-Mobile yesterday, and both my wife and I are having some trouble with our phones. Neither of us seem to be able to receive texts from 5 or 6 digit short codes. I've reached out to tech support who put in a trouble ticket. The engineer assigned to that ticket reached out today and claimed our account had no blocking, nothing was wrong, and blamed our devices or the sender. Since this is an account wide problem, its clearly not a device or sender issue. Any ideas what might be going on, and what can be done to fix it? ¡Gracias!

If it helps at all, we came from AT&T. Initially we had brought our phones from AT&T, though we've since upgraded to new phones. We also ported our numbers from AT&T.