Can't turn password setting to "ON" for admin

As far as I can tell, my admin user has no password and I cannot set one. When I go to edit the admin user the setting slider to the right of Password is set to OFF. If I click the slider a window comes up asking for a new password and confirmation. I enter the new password, twice, click OK, and then I’m back to the previous screen - slider is still at OFF.

Has anyone seen this?