Yes, that was my first thought too -- much cheaper design and construction of the syringe, purpose to reduce production costs. No problem if it doesn't affect function...
...which it hasn't. The new syringes are an improvement in my opinion -- the material used for the cylinder is crystal clear, so it's a little easier to manage and remove bubbles.
I have no doubt there have been some engineering changes to the pods. Nothing visible in form, but at the very least some software changes, and I suspect some minor changes to the insertion mechanism to deal with the sticking issue (i.e. inserting cannula, but not removing the needle without either a delay, or some tapping on the pod). Could be nothing more than a dab of lubricant on the brass lever arm.
In any case, 100% reliable so far, I'm on pod 14 now (I'm a T2 with IR, so I generally go 2.5 days on a pod).
The last batch (with the old syringes) I had before this was a disaster. Pod errors all over the place. I think I had a 20% failure rater overall. Out of 50, I had 3 give me pod errors during priming, and never even put them on. As some may recall from another posting, I had one simply stop communicating at all with the PDM after a day and a half.
So, my theory is that was the dregs, from the last pallet in the warehouse of some pretty old ones that they're finally getting cleaned out as the new updated design is rolling off the line.