SMS Verification Code is not received from a specific financial account on iPhone

SMS Verification Code Not Received from one particular financial account. I can receive the codes by voice but not text. I can receive 6-text codes from other businesses with no problem just not this one account. What I did to temporarily fix the problem was to go through the logon process as I normally would do and requested I be texted a 6-digit SMS security code. I did not receive the code as expected. However, when I checked my recent phone log the phone number used to send the code was in my RECENTS folder. So I added that number to my Contact list. And now I can receive the 6-digit codes where I couldnt before. Why is this happening to one account and no others are affected? This just started happending two days ago. phone is operating IOS26.1. My wireless provider is ATT. I also have ATT ActiveArmor activated.

[Re-Titled by Moderator]

Original Title: SMS Code blocked