I am using a Nexus 7 with the latest software from DJI.  I can connect to the Mavic and fly.  On occasion, I will get the message that I no longer have contact with the drone.  I have tried to restart my Nexus but nothing seems to work.  It will obey a RTH thankfully but cannot reconnect.  Any suggestions?

Did you capture a screenshot of the error message?
If the error message was "signal lost", it's possibly you ran into interference in that area.
Please adjust the antenna when necessary and fly in another open area to see if it's the same or not.

I have tried another location and still got a message of " not connected."  Not sure how to fix it.  Any other thoughts?  I wonder if this is only an Android problem.

It's a app bug... Had it once also, took off, suddenly Aircraft Disconnected. Couldn't fix it until I rebooted everything. I just landed it, because remote was still working.

Remote remains active, just the Nexus disconnects on every flight.  Now I am also getting a message to recalibrate the sticks after I upgraded to latest controller software.  Went back to previous version with the same problem.