If you see an even 200 points on your account, it's likely that this is a merchant under our Spend $20 Get $2 cashback category. These points will become available once you reach the $20 minimum needed. Each transaction is calculated as a whole and not by $20 increments. Any additional amounts over $20 are also not rolled over onto a new transaction.
Clicking on the specific transaction will give you more details and show other transactions from the same merchant that are smaller than the $20 minimum needed.