Starlink satellites are in a very, very low orbit - which means they "see" a fairly small patch of land. So if you're in eastern Ukraine, currently satellites #32581 and #44197 are above you, with #17994 coming soon over the horizon (numbers invented).
Additionally, they have phased antenna arrays able to narrow-beam your data pretty much to you (this is very useful as you can, among other things, recycle the exact same frequency for another user a short distance away).
Spoof GPS all you want, but Starlink knows you're not actually somewhere else, simply because of which satellites are able to talk to you right now.