A* pathfinding not registering walls as obstacles, even though it sees them

I haven’t been able to get help for this from the official A* forum, so I thought I would try here; maybe someone here is familiar with this problem.

I just started using A* pathfinding; this is my first attempt to set it up and incorporate it into my project.
I followed the tutorials I saw online. I scanned my environment and it displayed blue squares on the walkable terrain and red cubes on the walls.

However when I actually run my game the pawn using the AI scripts just tries to walk directly to its target, completely ignoring the path. It just gets stuck walking into a wall.

I don’t know what setting I need to adjust to get this working; I don’t know where to look.
Any thoughts? What should I be looking for? What should I try?

If this is about the A* Pathfinding Project Pro, then it has an example scene with that spider-robot thingy, open it up, check if it works on your machine and if it does, check how it was set up for the results. And/or it has great written and video ‘getting started’ tutorials as well.

No, this is just using the free package, not the paid asset that includes all the demos.