Not saying its the answer now, but I had a similar problem a couple or so years ago with Barclays. Apparently at that time, "Barclays only supported IE and no other browser" and actually knew of problems, but had "no time scale" to correct the problem. They eventually got around to sorting things out. and all as been well since (fingers crossed).
"I got round the problem of typing in the appropriate web address and then deleting the old bookmark and substituting the new on, and all is then OK". Possibly the best move, until things get sorted out.