if the borders of the mesh are all connected, it doesn't matter that the blue has breaks in it, but if the border is broken too, then you need to fix it,
1. if the steps are navigable, then use a connector in the meshgenerator to link the top and bottom of the steps, else
2. make a box to tell nav that is is 'walkable', or
3. adjust 'actor' abilities like 'increase the angle they can traverse a bit higher etc, and regenerate the mesh