I've had trouble with a password that I think I successfully used
once or twice, but which recently was found to not match (error is
that username & password don't match--you pick).

I got it reset to machine-generated one, and this time carefully typed in
(Editing my profile ...) my desired one (thinking that maybe somehow
I'd mistyped it previously ... ?).
The edit/change seemed to be acceptable--the system didn't balk or say that
I was trying to use invalid characters--, but again when I then tried to login
with the newly reset password, ... same problem.

I don't see in site info any rules for password construction.
I do know of ONE site that doesn't accept an '*', e.g., because it tells
you so if you try to use that. (I can only guess that something like
this is my current problem--there is, as I said, no indication of trouble
at the time of creating the password.)

What are the password rules?

*kN*