No Raytraced DistanceField shadow

Hi Everyone

I imported fbx file into scene while runtime
but there is no shadow if spotlight or pointlight be checked Raytraced DistancedField
未命名 -2.JPG

as below pic
8764133848e3eb877a6aa6931b2e3d9d0eb922b9.jpeg distancefield shadow for import fbx in runtime without build light

thx