Caller ID - Displayed number spoofing
If a bank scammer tells you to check that the number displayed, is the number on the back of your card, ignore this, because scammers can display any number they wish. Hang up, check you have got a line, then call yourself to see you are engaged! If you do not have a line, use a mobile if you have one, otherwise wait until you do have a line. You can then call the number on the back of your card to see if it was a genuine call: https://bit.ly/39mYFhl