I have had zero problems with Safari 15 or Safari Technology Preview (Safari 15.4) and any of my financial sites in spite of a recent spate of site hardening by multiple institutions.

AN ASIDE: My bank, which has depositors all over the world and only one brick & mortar site, no longer accepts on-line deposits via any browser on any platform, but they continue to accept deposits via their iOS app. I would love tor know the rationale behind that policy change.

If we knew what it was we were doing, it wouldn't be called research, would it?

— Albert Einstein