I use 2 apple devices to fly an Air 2s, mini SE and a mini 2. The app does not always sync the flight data. Sharing is enabled and the flight data exists on the devices that were in use but often only a truncated flight log is exported to the other devices. I had several 20 to 24 minute flights but 2 flights on each device show as only a few metres and less than a minute in length. I can play back the logs fine on the device that flew the drone. But only the start of the flight on the other device it just ends after it's shortened time.

To add some info latest firmware and the very latest app in use on the latest version of iPhone and iPad updates