Can't receive Short Code Text Messages

I am suddenly having trouble receiving verification codes from banks and other websites.  This was never a problem until a few weeks ago.  I've called AT&T twice and first was told to turn off my phone, remove the SIM card, replace it and restart.  This did not work.  Then I was told that the latest update is causing short codes to get blocked and I needed to give them the phone number of the bank and it would be unblocked, that hasn't happened.  My bank is currently giving me text messaging as the only option to receive a verification code to transfer money and I can't get the code.