This is a bit of a strange one, but I've got a few input methods on my computer. Two Japanese methods, plus Qwerty and Dvorak. Sometimes, and I've never been able to find out a pattern to it, the 1Password password dialog switches input to Dvorak, and doesn't allow me to change it. This means I have to launch 1p, and log in there, in order to use it.
Below is a screenshot, showing one example. Note the greyed out options, and that the keyboard input switch popup only lists dvorak: