Under Settings > Accessories Floodlight > Floodlight > Floodlight Control, I set it to Auto, Motion is detected by PIR sensor, and leave all other checkboxes unchecked. Like this:
Then I go into PIR Sensor Settings, and set them like this:
Of course you can adjust yours accordingly. My exhaust is a bit further away from the camera so I don’t have to set it all the way down.
I also set the camera Motion detection zone to exclude the areas most likely to get the exhaust passing through. Settings > Detection Settings > Detection Zone. This is just to minimize event recording.
Another thing is you can get an elbow pipe to re-direct your exhaust away from the camera. Not an option for me unfortunately since it’s either trigger the camera or kill the bushes nearby. Hope this helps.