Yesterday I flew the P3 until the battery had about 20% left and then landed it. I turned off the P3 and controller a minute after landing it. I checked the flight record in the iOS app and there was no sign of my flight. I turned the P3 back on and waited a couple of minutes and still nothing. Any ideas of what happened?

Did you login to your account before flight??That is weird... Even when GPS signal is weak or connection is broke the flight record will be saved...

Just for verification using an iPhone 6 plus I am seeing all my flight records which includes any photos you take during the flight