Sending move from API causes 500 error

Assuming a request of the form as suggested in documentation and around the forums:

make_a_move_url = “https://online-go.com/api/v1/games/”+game_id+ '/move/'
move = {“move”: “bc”}
game_headers = {“Authorization”: "Bearer " + player_one_access_token}
make_a_move_response = requests.post(make_a_move_url, json=move, headers=games_header)

Why should this create a 500 error on the backend?
Is something missing from the move json or is the move itself invalid?

pinging @anoek

Any answer to this?