It seems like the tests aren't thorough enough. if you reverse the list as if it were a singly linked list (eg ignoring all prev pointers) you get full credit.

Node Reverse(Node head) {
    if (head == null || head.next == null){
        return head;
    }

    Node newHead = Reverse(head.next);
    // head.next.prev = head.next.next;
    head.next.next = head;
    // head.prev = head.next;
    head.next = null;

    return newHead;
}