No, even if you allow partial path, the AI won’t be able to move since it’s not in the surface area of a nav mesh. Here’s something you can do though: How to make navmesh upside down? - #2 by MieszkoZ
I also found this free plugin on Reddit if you’d like to try it out: https://www.unrealengine.com/marketplace/en-US/product/customizable-pathfinding