Noticed when testing with NVDA: The pinentry window has a show/hide password button. This button is announced with (afaik) correct info by NVDA. But when one presses "enter" when on the button, its icon changes from an "open eye" to an "eye which is crossed out" and the password is shown on screen. Nothing further happens. There is no announcement that the password is now shown or that the button now has the function "Hide password". You can repeatedly hit enter, thereby revealing and hiding the password again and again without any audio feedback.
As a blind person you can only perceive which is the current display status by going back into the password field (Shift+Tab) and checking if the password is then read or not. When after this you tab forward again onto the show/hide button, the current function is announced correctly (something like "make password invisible" in case the password is currently shown).

I would expect that on toggle of the button's function, the new function would be announced so that the user can know what will happen wenn they hit "enter" again.

As suggested by @ikloecker, we could make the button checkable, this will cause an announcement "checked/unchecked" when the status changes.