"Photos" app shows different date & time depending on On/Off of 24-hour display in iOS when saving JPG files

I use PHPhotoLibrary in iOS to save JPG files to the camera roll.

There is a difference in the date and time displayed in the "Photos" app depending on whether the 24-hour display setting in iOS is set to On or Off when saving.

• When saving with "24-hour display: Off", the date and time in the Exif of the JGP file is displayed.

• When saved with "24 Hour Display: On", the date and time when the file was saved is displayed.

JPG files are saved with the following code.

HPhotoLibrary.shared().performChanges({
    PHAssetChangeRequest.creationRequestForAssetFromImage(atFileURL: jpgFileUrl)
}, completionHandler: { (success: Bool, error: Error?) in
    print("success=\(success), error=\(String(describing: error))")
})

Is this an iOS specification or a bug? Or is there a problem with the code?

I would appreciate it if you could provide me with some information.

Thank you in advance.