Duds ?

Unlikely, but if your PJ's look to be in reasonable condition, they might have been sprayed with a sprouting inhibitor.

If so, the inhibitor could well be inside rather than on the surface of the tubers, but it might be worth giving them a good soak in water in the hope of reducing the effect.

I'm assuming the KE's chits are long and white if they've been kept in the dark - they all need to be in a reasonably light, frost-free place at this time of year.

I'd recommend snapping off the longest of the chits - if they avoid drying out and shrivelling away beforehand they'll still be likely to snap off anyway when planting out.

The tubers should produce a few new chits before planting, but it doesn't really matter if they don't as long as you've got a few strong green/purple chits on each tuber.