Character Groom Hair Ground Shadow disappear when not look at the character

Hello Lovely Community, I have a freash question for you guy to solve. (Please send help)

My scene have a character with groom hair, ground and a directional light. When I look into the shadow of the character only, I realize it doesn’t have the character hair. Which the hair only appear after I also include the character hair inside my view.

I tried to increase bounds for both character and the groom hair but get no luck. FreezeaRendering show the hair is still be rendered. What could be the problem? THANKS