It's probably the shadows activating the line crossing...
If the camera has something like Hikvision AcuSense you can select human to avoid the false alarms.
"Hikvision AcuSense technology uses a filtering system to classify targets as humans, vehicles, or “Other” objects. With a powerful deep-learning algorithm at its core, it can intelligently differentiate between moving objects like shadows, leaves, animals, and other such unexpected movements."
Just noticed you have camera model Hikvision DS-2DE2A404IW-DE3 listed in your post so you should be able to be select the target detection under line crossing as human and set target validity to higher or highest.
