I had a similar issue with the stay 7 nights, get 10,000 points promotion but it went in the opposite sequence of yours. I registered in late September. I had a couple stays in very early October and those stays did not post. I stayed again earlier this month and noticed the nights from those stays posted toward the promotion.
Both rural HIX properties. No sign of an exclusion or similar.
I e-mailed customer service and they reconciled the situation by crediting me for the nights stayed in early October and the points then posted to my account as an adjustment.
I was not targeted for the offer.