I think it all comes back to Smartthings.
I posted about this here Using SharpTools with ST and Tasker for presense sensor as I have had issues with my new August Lock. As you can see in the thread I am still having trouble but getting closer.
Options #1 - [HOW TO] SmartThings Presence reporting using Tasker/SharpTools/AutoLocation
Option # 2 - [RELEASE] Improved Mobile Presence (Android only)