Deleted

It's normal. It happens when a giveaway you entered is deleted. The points are returned to you, making it so that you have your original 400 + the difference.

If you check your Entered Giveaways page, you'll see one or more marked as Deleted.

If you leave a giveaway, or a giveaway you entered was deleted before it finished, you will receive a refund of the points you spent. If you already had 400 at that point, the refund will put you over the limit, but you will still not accrue any more until you are below 400 again.