Missing activity on ring camera

Hello, can anyone help me understand this.  At 7:28am I went outside to wait for a grocery delivery. (Ring camera caught me exiting my front door) From 7:28-7:35 the entire delivery happened right in front of my camera but nothing was recorded and no motion was detected.  At 7:35am my ring camera was live viewed but the delivery had ended and there was no one in front of my camera, basically nothing to see at that point.  What happened to my entire event of my delivery? 7 minutes of activity and not one single motion detected except when I went outside. How does this happen?