Sure enough, your magnet is messed up. And it has 10 poles.
It would be possible to make one from aluminum or plastic with some tiny cylinder magnets inserted into holes. You'd need to space the holes very precisely and make sure the magnets were inserted to exactly the same depth.
Hard to say why it failed. Possibly it was rubbing against something and heated up enough to demagnetize that spot.
It would also be possible in theory to re-magnetize the spot, but that might be hard to get precise enough.
It would be possible to make one from aluminum or plastic with some tiny cylinder magnets inserted into holes. You'd need to space the holes very precisely and make sure the magnets were inserted to exactly the same depth.
Hard to say why it failed. Possibly it was rubbing against something and heated up enough to demagnetize that spot.
It would also be possible in theory to re-magnetize the spot, but that might be hard to get precise enough.
