I had one upgrade to my bank, and had it completely full 70/70. I switched to my alt that I haven't used in a few days, and as I did my alt received another set of CE mail with items. Then I went to open my bank with my alt and it was showing as 0/60 empty, and the 1000g upgrade available. So I backed out and grabbed my main, and when I opened my bank it was showing full at 60/60. And the 1000g upgrade available as if I never purchased it. So I lost my bank upgrade, and lost the items I had in those 10 slots. Which I'm sure included some heavy armour I was waiting on researching.
Has this happened to anyone else?? Yes, I've already submitted a ticket on it. It's just not really fun to continue right now with some storage/items loss.