I have an Apple watch 1 with watch OS 3. My MB Pro is Late 2013 running OS Sierra. This morning i upgraded to sierra and activated 2 factor auth and unlock my Mac with my watch. For 2/3 hours it worked absolutely fine (so i know it works!). Now all of sudden it's stopped, and the option to unlock my mac with my watch has disappeared from the options menu. I'm signed in to iCloud on all devices (1 account), i'm wearing my watch, i'm close enough to the MB etc... Has anyone else experienced this? Seeing as i haven't changed anything settings-wise i'm struggling to find the root cause It seems like the option has been deactivated somewhere? Maybe it's a bug? Anyone have any ideas? - Screenshot of the missing option is attached. Thanks!