Security cam not detecting motion

I, too, am having the same issue with things not appearing on camera. This morning, a large FedEx truck pulled in the driveway directly in front of the camera. The doorbell caught him when he dropped off the package, but the spotlight light cam showed nothing of his truck arriving or leaving. The same thing happened last week when landscapers were there… they dropped off a trailer the night before working and I happened to go outside and discovered the trailer. No evidence of them coming or going. When they pick it up the next evening… nothing. But every car that drives down the street or when I’m outside mowing the yard … gotcha! This is getting very frustrating.