While the "Delete After Use" setting is designed to improve security by automatically removing OTPs (one-time passwords) after they've been used, it doesn’t ensure instant deletion across all platforms or scenarios. The actual behavior of this feature can vary based on the app or service utilizing the OTP.
For instance, some services may process OTPs locally on the iPhone and immediately trigger the deletion. However, others might rely on backend systems or APIs that could delay acknowledgment, meaning the OTP might remain visible temporarily. Furthermore, the deletion feature may also depend on how the specific app integrates with the iPhone's OTP autofill system. If an app or service doesn't fully support or interact correctly with this system, the OTP might persist longer than expected.
Therefore, while "Delete After Use" adds a layer of convenience and security, its effectiveness can be influenced by external factors, such as app design and third-party implementation. Users should remain aware of these limitations and verify the feature's behavior with critical apps where security is paramount.