I can't log into my bank app with Safari 15

There have recently been many reports of new problems with Safari. It seems that the recent Safari update has issues. Word has it that Apple knows about the problems and is working on a fix. I assume that it will be released fairly soon. In the meantime, use another browser such as Firefox or Chrome and they should work for you.

I had the same problem, but this thread solved the issue for me on Catalina https://discussions.apple.com/thread/253165554

I couldn't update Safari, but the Safari reinstall fixed the problem.

Similar issue over Here https://discussions.apple.com/thread/253164293

When Apple released the Safari 15 - they implemented the Auto Change from an URL showing http to https and wondering if this comes into play with your issue ??

I don't think there are any bank apps that are NOT https://

I can connect to my bank site just fine, but I can't get the text message to confirm my device. so I can't log in.

everything works fine with Chrome. Ugh.

most other web site I use work ok, EXCEPT Sirius XM radio has no audio !!