Welcome to Android Central! Do you mean that you have an LG V10? Are you certain GPS is turned on in Settings>Location? Also, make sure Pokemon Go has permission to use Location Services. Go to Settings>Apps. select Pokemon Go, tap Permissions, and check there.
I also play with a V10 and get the GPS not found messages at times too. It doesn't seem to affect the game at all. I still find and capture pokemon all over.