Not receiving bank 2fa texts after switching SIM cards?

Trying to purchase some clothing online, and have 2fa enabled. For example, when I enter my card details on a site, before I’m able to finalize the purchase, I have to verify a code sent to my phone. I have a main SIM and an old SIM, which is the one linked to my bank. So I swap the SIM over, get the code sent via text, yet I’m not receiving it at all. My iPhone 13 is registering the SIM, as it updates the number, but I’m not getting the text. I’ve waited 5-10 minutes, still nothing. Yet this same thing used to work when I had an iPhone 11. No idea, any help would be appreciated.

Did you get a new number with the new phone? If not, the messages should be going to the new phone/SIM, not the old one. If you did get a new number, unless you’re paying for the old one too (so two lines on the account), that old number won’t work anymore.

SMS messages go to a telephone number, not a SIM. It sounds like your new SIM has a new telephone number. You’d need to know your new phone number, then notify the bank of the change. You’d probably make the bank change through the bank’s app or website in your security settings.