Run as administrator now is broken the second time for me again after recreating user account locally.
Neither on the command line nor via the context menu I can run as programs as an administrator for a (non-admin) user. A user/password prompt is shown but nothing happens. Also explorer deletes are not exectuted after successful login with admin priviledges. Everything after successfully being prompted for admin credentials.
Again: Run as different user and then running as administrator (without additional credentials) works. Also elevation works for the same user if granted admin priviledges. Also works for other users.