No dynamic shadow on translucent material (Mobile)

Hello,
I am moving a scene from UE4.16 to UE4.20. I see many thing changed.
In UE4.16 translucent material receives dynamic shadows, however in UE4.20 they do not appear.
Are there some settings to enable to get dynamic shadows on translucent materials?
UE4.16 worked perfectly, UE4.20 doesn’t show this shadows.