@Moosemilk have you looked in the detection settings of the camera in the Tapo app  and (if available) checked that motion detection is off perhaps. Or turn down the sensitivity?

You may have an option to only detect vehicles and people.

Motion detection, if enabled, detects all movement, so light changes or trees moving etc will trigger a notifcation. I have this turned off for some cameras and only have it set to vehicles and people detection. I have also tested and adjusted the senstivity to get it just right to how I want it.

Your notification will tell you what event triggered the alert so that will give you a clue as to the cause.