Power Issues - Freezing temperatures can kill batteries and temporarily limit the effectiveness of solar panels. To overcome this, use Energizer Ultimate Lithium AA batteries during the winter.
Dirty / Scratched / Damaged motion sensor - Your motion sensor sits behind the curved brown rectangular covering on the front of your camera. Over time, dust and dirt can accumulate and make it tougher for the motion sensor to detect motion. Try gently cleaning and inspecting this motion sensor covering. And email a picture of it to support@yellowstone.ai and we can review it for potential damage.
Mount - for most situations, the camera should be mounted 3-4 feet off the ground. The motion sensor is most sensitive in the middle third your picture. Try tilting the camera so that the activity you are monitoring occurs in this area.