Years back ... I guess I'm getting old, I thought it was still a new product.
What you are experiencing is not uncommon. It's generally a good idea to check your point of aim when you buy a new lot of ammo. As consistent as they are, I have occasionally had to adjust my sights even when it was the same brand.
It's a shame the group size is larger. That's a different problem entirely. But 2 1/2" is still plenty good for deer.