Bad Batch of Strings?

It's the school holidays and I was busy with a lot of stringing and customizations. One after another. Almost non stop. 

With the Black Friday sales and Christmas mood, many were testing new string setups. Almost all wanted more spin.

Strangely, there was one poly string that kept snapping during tensioning. After the initial string snap, every single grommet hole was scrutinized thoroughly. All was in order.

The string gripper and clamps were stripped apart, cleaned and checked before re-assembling. 

The poly string was also examined for kinks, nicks or other damages. None were found.

But when I applied tension on the mains, it just snapped. Not very tight, just 50 lbs on a 1.23 mm shaped poly.

Sustained a small cut on my left arm from the string lashing. Guess this is all part of stringing. Another reason why I just cannot like poly...

Should be a bad batch since I cut it out from the reel. At least it was not as bad as my previous lashing (link).