Items dissapear if you put any items in after your bank is full, you can retrieve them by like emptying a bankslot, it'll move onto there then :I
Yeah it's like there are hidden extra rows
It's the client vs the way we do item storage- the client only shows so much but technically you can have an infinite amount of items stored :)
This has been filed and issued.
Reference: blitz/bank/issues/#16
- Dev Sean