It's something I've noted before, and checking mine in the past all show a faint magnetism near the caps, and including this one and a few others that have come through.
Here's a picture I took of one some months ago:

The magnetism is pretty weak through the casing, and
While it is possible that yours are magnetism free, the ones I've handled in the past year have been magnetic, which is a disappointment considering their marketing and price.
For all I know, it may have come down to availability during the time i baught them, but it's still disappointing.
I'm aware it's not perfectly apples to apples, but it was never really meant to be.