Why are events missing from my history?

Hello, So i keep having events missing from my history, my internet connection is great, so i wonder if it is a device issue? Two things happened today for example: Courier came, rang bell then left parcel. My history only shows him arriving not leaving. My kids put went outside to get the bins. The history showed them going out the gate and outside to get the bins. Then ended and didnt show them coming back in with the bins right past the doorbell. Any thoughts? Thanks *M