AI Climb Steep Slopes?

Lately I have been working on a mini zombie game just for practice and everything works fine from survival waves to picking up weapons. But one little problem concerning AI moving up steep slopes has me at a bit of a standstill.
I am using the Unity NavmeshAgent just for navigation across my terrain but setting the targets via a script. The ai can move great on flat terrain but when they have to move up a hill, they just can’t climb it unless I give them a very high speed. I would like some pointers to help me have ai climb any slope regardless of their speed. Can someone help me?

In unity go to the window tab at the top. Then select Navigation. this will bring up a window on the right where the inspector usually is. Once you have this up, go to bake and then edit the max slope variable via the slider provided. After you have done this, you will need to re-bake the navmesh in order for the mesh to be updated. In addition you can play around with the step height to see if that helps.