Can't change managed account password

Can't change managed account password

I am trying to change a managed user account password in Zoho Mail.  I am logged in as the domain administrator.  I can edit the managed account user, enter the new password (twice), and my admin password.  When I click OK, nothing happens.  Nothing appears to be happening.  I don't get any errors, no notice that maybe I don't have the right set of characters in the password.  What am I doing wrong?

Thanks