$3 Big Macs from a two week old promo

Am I the only one who has been doing this?

A few weeks ago, McDonald's announced that they were improving their Big Macs, Quarter Pounders, and basic burgers with smaller cook orders, (sometimes on-deman) and cooking the burgers with the onions, as well as warmer buns.

Between Aug.13 and Aug.19, they had a promo on where you could order a Big Mac for $3 to try this new version.
During this promo I had ordered a couple (or three) in that time frame through the Mobile app.

Well, it's September 2nd, and I'm STILL ordering them for $3... but only if I "re-order" from a past mobile order.
If I try and create a new order, it comes up at full price ($5.79 in my area).

I can add/modify the order (add a drink, change the quantities, etc) but provided I start with a "re-order" of a previous $3 Big-Mac order, it still rings them up at $3ea.

Anyone else notice this??

The above trend continues with Summer Drink Days promo.


EDIT: The $1 drinks was put to an end today in my app (Sept.9) but the $3 Big Mac STILL works