Welcome to the forum.
I started winding with a Dewalt battery powered electric drill.
It was a half inch drill.
I chucked a cutoff half inch shoulder bolt in the drill.
I had the head machined flat, and I super glued a piece of plexi glass to the bolt that I mounted the bobbin to.
I had the same issue you do, with the wire pileup.
If your bobbin mounting board is not mounted exactly straight, you have, what machinists call run out.
One end piles up on one side, and the other end piles up on the other side.
So the issue is with your mounting plate board, mounted to the winder spindle.
With the pickup off the board spin the board and see if you can see the run out.
While it is spinning hold a pencil close, and you should be able to mark the end, sticking out the most.
Other than that, your pickup looks fine.
** If anyone has a point to add, please do so.