New Xfinity iPhone SE won't receive authentication texts from banks

I suggest that you power off then power on your iPhone. There are probably some things that are still happening in the background between Verizon, Xfinity, and other servers that are still refreshing, and hopefully these will all be resolved overnight. 

In the morning power off and power on again and hopefully you will be good to go!

Unfortunately, it didn't work. I'm visiting the store in person tomorrow to see if there's anything more they can do. If not, it looks like I need to persuade my bank to delete my online account so I can start over. Don't know how easy that will be. They said they could not delete my 2-factor authentication.

Many banks have three options? Text, phone call, or email. And, if text fails several times, then they offer to call you or email you. 

If and when you get some resolution, make sure that you click on the option for them to recognize your new device so that they don't ask you for 2-factor authentication each time. 

I know folks have gotten beyond this issue, but I wanted to clarify something for my own edification

If I understand correctly, Xfinity Home phone service is VoIP.  Xfinity Mobile phone service is an MVNO on Verizon Wireless, though depending on your phone, you might have WiFi voice calling and/or VoLTE voice calling, both of which use some form of data connection rather than mobile/cellular voice service.

Is that correct?

You are mostly correct. Most cellular calls are now VoLTE which is voice over LTE. So both voice and data are now using LTE which actually uses IP protocols, but because you are still using cell towers they don't call it VOIP. Carriers don't charge you and you never see the amount of data used for phone calls or SMS. Xfinity Mobile does usually charge you for the data used for MMS. 

When you enable WiFi Calling and you have a weak or no cell signal your phone should switch from Xfinity Mobile to XM WiFi and your Phone, SMS, and MMS then go through the internet to the XM/Verizon servers and could arguably be called VOIP. 

I've seen in other forums that the problem with not receiving bank authenication texts is related to this Xfinity Mobile feature called "Premium Messaging Block", and others have had their problems fixed by having Xfinity disable the "Premium Messaging Block" feature.

I am currently having the same issue with not receiving bank and other online account authenication texts, but when I spoke to Xfinity support, they stated that "Premium Messaging Block" was not associated with my account (I'm not sure I believe the support person I was speaking to).  Can anyone else add validity to disabling this feature as a possible fix?

They removed it from mine this morning and this has not resolved the issue. It is incredibly frustrating as tier 3 / verizon says if you can get other messages then we are not blocking short codes.

I have a Pixel 5 - I'm not getting 2-step codes now either.   I discovered this week.  I cannot receive the text to register for V-Safe (CDC vaccine monitor program) - and now I cannot recieve the 2-step authenticator text from Playstation.

Why don't things work the way they are supposed to 😞  ugggggh

IDK if xfinity did anything on their end - I was on the phone with their tech support.  They had me reset network settings (Pixel 5).  Now I'm getting Authentication texts 🙂

Call Xfinity and ask them to disable premium message blocking, this is an anti spam feature xfinity moblie uses, and it could block short codes.