I suspect, somehow, that this is stupidity with the bank's processing core systems, which ... things are weird with financials.

They buy someone out, and now there are two systems. Glued together with duct tape. Then they release a new web product, or mobile app, or whatever, and that gets taped on too. Duct tape and spit all the way down, with everything eventually limited by the most broken part (if you're lucky).