How do I use Links?

I’m using a Grid graph which is working fine for pathfinding. I’m trying to create links at the moment.

I’ve created two game objects each with the Link component and have an end point of each other. My character navigates to the first Link object and moves to the second which is on top of a cube. However, when moving to the end link the characters passes through the cube instead of raising up to the end link point when moving to the end link. The top of the cube is showing as part of the grid and the bottom isn’t. When I added a ramp, the agent did move on top of the cube without using the link.

Why is my agent (rigidbody) not moving vertically to the top of the cube and also somehow passing through the bottom of the cube which it can’t do if the end link is not there?