entering passwords on Focus 40 Braille Display in IOS

Braille on Apple Products

Hi all. wondering if anyone can help me? when trying to enter passwords in to, for example, ITunes, using my Braile display and an Iphone 5 I find I am unable to. When I am in the box, I enter the password, which appears briefly on my display before being replaced by symbols presumably to denote that the password is hidden on screen? the problem is, it seems to enter far more symbols than there should be for the password and the password is then not accepted. does anybody else have trouble entering passwords on Braille displays or is there something specific I need to do?