GUI Authentication Requiring a Different User Auth

A few weeks ago a colleague signed into my Fedora 22 workstation. He too is a group admin. Ever since then whenever I attempt to install or unlock the "Authentication Required" modal requires his password and not mine. How can I fix this? It's highly annoying. One thing I need to point out is that my workstation uses winbind for LDAP authentication. I'd love to switch to sssd, but I just haven't had time to rebuild my profile.