Hey, I'm the OP, just made an account. Thanks for helping!
I have a Nexus 5.
Yes, when I tap deactivate for the Android Device Manager nothing happens, I go back and it is still checked and activated.
Update though, I went to Settings>Google>Security just to mess around and deselected both "Remotely lock this device" and "Allow remote lock and erase" and they both deselected. Then I checked my device administrators and NONE of them are selected, so Android Device Manager became deselected that way. It's not what I actually want so I went back to Settings>Google>Security and reselected "Remotely lock this device" which worked, but I tried to reselect "Allow remote lock and erase" and it takes me to the "activate device administrator?" page for Android Device Manager and the activate button won't respond, which is the issue from the beginning. The "Cancel" button won't respond either. Nothing happens. It doesn't glitch or anything. I just have to hit the back button and shrug my shoulders. This happens for any app I want to make device administrator.
I'm not sure what you mean by asking me if I'm logged in as a Guest User.
I am logged into my google account if that's what you mean.
Cheers!