Neighbors stopping my motion notifications

Hello. I have a really bad neighbor situation which is why I bought the cameras to begin with. I have the wireless outdoor stick up cam. My neighbors are using something to stop my cameras from detecting motion. I don’t see IR light anywhere that I can tell. And I can use live view just fine. But no motion detection. What could they be doing & is there anyway to prevent it? Thank you

Did you check your camera to see if they’ve physically put anything over the sensors such as tape?
Did you verify the settings for your camera that you have it setup to detect motion on your property?