Pokémon Go has made changes to Pokémon spawning as protection against spoofers.
Recently changes have been made to the way Pokémon spawn in Pokémon GO. Prior to this update, if multiple players found the same Pokémon, other than the CP, everything about the Pokémon from moves to IVs was the same. Now, however, for all users under level 25, there is a complete randomization of stats, moves, and CP. For users about level 25, the old system still applies, with only CP differing, and for users above level 30, everything including CP will be the same.
The main reason for this change is to prevent spoof tracking. Many third party apps were able to locate Pokémon with ideal IVs, moves, etc. and therefore allowing GPS spoofers to find the perfect Pokémon, then chase it down without even moving a muscle. This randomization will make it much more difficult for third party trackers. How? Well, third part trackers locate these Pokémon and identify their stats through randomly generated low level accounts. Therefore, by randomizing the Pokémon below level 25, third party trackers will still be able to locate the Pokémon, but not the stats. So while this will not prevent spoofing, it will definitely put a dent in its effectiveness.
For more information: Pokemon Go Makes Huge Change to Pokemon Spawning
