Is it possible when you're checking your own location at home, you get a very contant location and suddenly you get a different location?

Is not accurate like really. But just enough to know where.

Yes even with maxis friends finder u track someone then u ask tat person r u at tat location the person will say No

i think its guessing by comparing with different broadcast stations nearby, however not that accurate if that area only have 1 or 2 broadcast station, it will take the nearest one...

for kl side, it is quite accurate last time when i tried....