unity – Nav Mesh Agents are not moving along the mesh

I’m fairly new to unity.I’ve been playing with Nav Mesh Agents lately.I have encountered this problem twice.The first time I didn’t bother redoing my project all over again.But now its bothering me too much.

I initially had a NavMesh baked along the road in my game.But later I had to change the layout of the roads, hence I had to rebake the Nav Mesh.

But now I’m having the problem where the agents are not moving along the Nav Mesh to Reach the destination, but instead they “try” to move along the shortest path.As a result of this all agents gather to a point rather than moving along the track.I’ve shown below a picture to better illustrate my problem.

Issue I have

They try to move along the red line instead of going along the road and then getting to the destination.

I’m pretty confident that nothing’s wrong with my code because it worked earlier and works well in other scenes.Is there anything I missed when re-baking the Nav Mesh?Any help to get the agents to move along the road is much appreciated?
Thanks in advance.