Can not track my child's location

I have subscription to Norton Family Premiere. My child uses a LG-D415 (android os 4.1), and Location Supervision is turned on.

Problem: When I tried to locate him (I know his device was online), pressing "locate now" on the Norton Family web site did NOT give me his CURRENT location. The webpage gave out-dated location information, something like "Updated 2 hour(s) ago at 12:28PM EDT".  Please help!  Thanks!