Android not letting me check for updates

[Android Central Question]

I'm using a Samsung C7 on AT&T running Marshmallow 6.0.1. When I try to update software through "settings/about device/software update" by clicking on it nothing comes up. I've tried the soft and hard reset with no results. My daughter, who has the exact same phone as me, was automatically updated months ago. Now I'm having software issues (hence the hard reset) and I'd like to see if doing an upgrade will fix it. Any help would be appreciated.

 

[B. Diddy]

Welcome to Android Central! Did you get the phone directly from AT&T, or unlocked from somewhere else? What's the exact model number, and what build number/security patch date is it on?