Setup, Bone Nut and Pickup Repair on Squire Super-Sonic

I’ve never seen this before, some how the magnetic poles on the magnet on the bridge pickup of this guitar flipped 90 degrees. I made these PAFs sometime last year and it’s possible that I somehow this slipped passed me but still, how did they move in the first place?

I re-magnetised the bar magnet and swapped the poles so South was on the outside which is standard.

Setup with a new bone nut this feel good.