Actually, the system is glitched (or whatever reason), has been for a while. When there is this 5 item limit sale, the system will actually apply the discount to more than 5 different items. Ever since I discovered this by accident, I have tested it by purchasing much more than 5 different items & every time I have received the discount if the cashier doesn't care to notice.
At first I thought buying multiples of a same item only counts as "1 item" for the coupon 5 item limit but I tested this theory to not be true.
When I said "if the cashier doesn't care to notice", they know the coupon policy but usually won't go out of their way to correct the discounts over 5 items. One time during that sale the coupon didn't get scanned, went back the next day (sale was over) & kindly explained to a cashier. They applied the discount for me (manually) but would only apply it 5 of the items (I didn't complain of course)
But your miles may vary. I'm not the only one to report this glitch happening.