Don’t swipe up on Days Since when you’re done.
iOS syncs your changes to the cloud about a minute after the change is made. If you return to the Home Screen before that happens, iOS will send your latest changes up to your iCloud account as soon as you leave. If you’re swiping up on Days Since, it’s unable to finish syncing your latest changes.
Swiping up on apps immediately kills the application and prevents it from finishing what it was doing.
Swiping up on apps is unnecessary and should only be done if an app becomes unresponsive.
https://www.businessinsider.com/apple-you-dont-need-to-close-iphone-apps-2016-3