This usually happens for the following reasons: 

#1 You were in a rural location, around a lot of buildings and/or vegetation so the satelite had a hard time finding your location.

#2 Your device is older.  

This  process is only allowable when you have uploaded more than 100 images. (We want you to understand the process before allowing for changes.)

From the life information page

#1 Scroll down to the Grave Site and click on the pencil

#2 Click on the pin and drag it where it belongs. ( For closer detail, if you click the "+ and -" keys at the bottom, it will help you zoom in.)

#3 Once you believe it is in the proper location click Save location.  Please allow for a 24-48 hour window to update the website.