Call forwarding fails on my iPhone 13 mini after iOS 18.4.1 update

I used to use call forwarding everyday since the cell coverage at my house is not great. I set up a favorite that dials *72 and then my home phone. It has worked flawlessly for YEARS. Ever since the latest update, the call instantly fails. I can make other calls normally. I have tried restarting the phone several times. I even did a reset on the network settings. Still fails. The *73 to cancel forwarding works fine. I can't even manually dial the forwarding.

[Re-Titled by Moderator]