You won’t find a solution in the light options. Your best bet is to use a raycast from the player to the light source.
First put all the objects that can case a shadow into an object group (say called ShadowObjects), and then raycast from player centre to the light source centre testing against ShadowObjects. Keep the behaviour disabled while the raycast returns an a ShadowObject.
This will work if more than half the player is out of the shadow.
If you’re having trouble getting to grips with raycasting, just ask on the forum; that’s what it’s for. If you can provide a code snippet of what you’ve done, someone will be able to help.