One that happens and not easy to spot is hitting 3 wood from a severe up slope. The ball actually hits the ground just in front of you taking a load of distance off. I've seen a few replays that show this.
But you're right. I've had shots come up woefully short recently. It could just be that I didn't really hit the club I thought I'd selected.
WGT admins have stated that the wind gusts.
Then there's just plain old VEM. About all you can do is mutter WTF to yourself and move on.
Good luck.