Geo Coords Slightly Off

My pen: https://codepen.io/bakecaker/pen/dZWXNR

So I was working on this today at work at the geolocation was showing the correct area (Marlton, NJ, USA).
I’m home now working on it again but the location its showing is wrong (Greentree, NJ, USA, showing on both my laptop and my home PC). This area is adjacent to my work area. But when I run the pen on my phone, it shows the correct area (Runnemede, NJ, USA). Runnemede is about four or five miles from Greentree. Any idea why this is happening?

Hi, I also encountered your problem, I found multiple articles about it and this is the best explaination so far.

http://www.andygup.net/how-accurate-is-html5-geolocation-really-part-2-mobile-web/