I was just about to mention the cooldown window. You said that the sensitivity of your cam is 84%, which is pretty high.
It’s very possible that the cam picked up motion from something else such as a tree branch before you walked outside.
Based on the timestamps of the videos above, you should have received a motion notification for the second video only which has the earliest timestamp. The two other videos are both within the five minute cooldown window and you won’t get person or motion notifications on them.
Have you tested the cam in an indoor setting where outside factors are not likely to trigger motion?