I changed bank - I had an account with a bank (RBS?) in the late 90s / early 00s, couldn't access it from linux, yet I could access HSBC, so RBS lost my custom.

My current bank (Smile) works in Firefox on linux, so that's fine. If it didn't, they'll be losing my custom.

Sometimes I am astonished by the life other people apparently lead. For example when they'd invest the energy to switch their bank (and all that is attached to that) over using a different browser to access a singular website.

I do not understand. It boggles my mind, in the most curious way.

Sometimes the way it fails gives the impression of a less-than-comfortable level of competence with technology. I also almost switched banks when my first was acquired by another, its webui was so much worse.

Please see the sibling thread (to your comment) for why I'm not going to do that. This "glitch" is probably intentional.

Also, I have actually tried to communicate with that bank about a far more important issue. It was frustrating and pointless, starting with the fact that they don't have a customer support email address.

As it’s a bank I suspect their devs have to use IE6 and have recently upgraded to IE8 and thus change in behaviour.