Ring Doorbell 2 missing activity

My Ring video doorbell 2 sometimes misses activity. last night it made a recording at 7:48 pm and then at 8 pm I looked out front by chance and saw a package on my porch, well within my recording zone setup. The delivery of the package was not recorded. I checked the ring history and nothing was recorded between those times (12 minutes). It recorded me going out to retrieve the package. This is the whole reason for purchasing this device as I had a package stolen from my porch before. Why did it not record that activity?