This is such a weird comment, reversing of transactions happens for mistakes on checking accounts too, such as a deposit to the wrong account.
On top of that the vast majority of people don't get a notification every time a transaction happens on their checking account. Some banks are implementing a notification feature for some transactions nowadays, but it's rare, new, and opt-in. The general case is money just flows in and out without much fanfare.
Some banks show you transactions that are pending. If a transaction never goes from pending to settled then it literally just disappears without a trace. Standard behavior.
On top of that the vast majority of people don't get a notification every time a transaction happens on their checking account. Some banks are implementing a notification feature for some transactions nowadays, but it's rare, new, and opt-in. The general case is money just flows in and out without much fanfare.
Some banks show you transactions that are pending. If a transaction never goes from pending to settled then it literally just disappears without a trace. Standard behavior.