Degraded Camera Sensitivity

[sea00]

My cameras are not picking up activity. The sensitivity seems to be degrading over time. The batteries are charged, the cameras are mounted above 7 feet, and the signal to the cameras is showing as strong. It seems that the activity needs to persist for a significant time to be recorded. It is not picking up people walking through the field of view or animals lingering long enough to eat my plants. 

I have increased the sensitivity of the cameras with no change. 

Any suggestions? 

[jguerdat]

Is the majority of motion across the FOV or more directly at the camera?