Happens to me all the time - I get points on award stays with literally nothing on my bill. I just got about 1300 this week - no bill at all. Even the actual folio doesn't show any spend (and also doesn't show nights, which did also post).

I do often think this is related to the way breakfasts are taken off for Globalists and GoH.

For many years, I would get a ton of points when using suite upgrades on award nights. But that 'problem' has been fixed.