Either:-

1. The one who wrote the chords basing on different key
2. You missed capo instructions
3. Artist retune guitar.

Musician can always change key, either for easier playing or easier singing. Up to you, just make sure all the musician in the band playing same key only.

And then verify yourself, because volunteer contributed chords sometimes gila off punya.

Yes that's true. And sometimes the person transcribing just got lousy hearing (or too used to certain types of music) and can't tell the difference between chords, resulting in a whole bunch of I IV V chords and missing all the inversions.