Are you sure nothing is there? I zoomed in on one of mine and found a rat. The sun and moon can also come and go and PIR will detect It. Technically, it is not movement in itself that the camera detects, it is a change in the total Infrared heat value in front of detector. As this heat signature increases or decreases the camera detects it, be it the sun, moon, bugs or leaves. The closer the object is to detector, the greater effect it has on changing heat value and increasing detection.
On most cameras, the Field of View and Detection Zone are different angles, often with Detection angle greater than FOV. That relates to an area that increases with distance and is outside of FOV that won’t be seen by camera. You can adjust “Zone” setting to “Centered” and slide the shutter up in front of PIR to counter this. In effect, this will subdue or decrease the complete detection angle. I haven’t tested the degree of this change.
10 min delay is way too long for me. Unless it is tons of blank pictures, it doesn’t bother me. Try changing cameras or change setup. Look for limbs and leaves that may move in wind. Also look above eye level. Basically anything that is on a picture that moves has the potential to trip detector.