My wife’s machine is a Dell I5404 2-in-1 (running Tumbleweed) that autologs into her account. Recently, when it locks the screen, it will sometimes not allow typing the password in, or sometimes allow typing, but will not unlock (Screen shakes and returns “Unlocking Failed”. In any case, she can’t get back into that session.
If I switch user to root at the lockscreen, it logs in fine, with the same password.