Two characters e.g. Aa (works).ok, i'll give it a look, but what do you mean by "Char" ? i havent changed it, but its pretty basic password
One character e.g A (allowed to be set but won't work).
This also means that if you had displays previously that didn't have a password set. They kind of do now with spice. So removing the display device and adding anew would probably be the easiest way to change this. And to make sure no old password is borking things up.
But as I mentioned. This is only an alternate idea. And might be an unintentional red herring/rabbit hole. The underlying issue might be completely different.