Thank you for the very informative reply, Tom.
#2 really applies to our situation. We are in SE Asia and the flour is imported from Italy. I imagine that it is sitting in the bag for quite some time by the time it gets to us. From the way the previous dough felt, I reduced my hydration by 2% yesterday to try and get back to normal. it was a pretty good guess. It was very close. I think I was no more that .5% off in my estimation.
I would expect variations in lots, but I was really surprised that the absorption rate changed as much as it did. I will be opening a new bag in a couple of days. No idea what to expect from it...