This is following on from my investigations where the AI fell through the floor. It is possible that the problem is, where you have very uneven walls, the AI can get close enough for them to lift the AI off the path. If this happens enough you end up with the situation where the AI is high enough up that when it does drop the ray that should save it will have already passed the collider on the floor.
Here’s a shot of some AIs being picked up off the path (with lots of lines from the A* navmesh and my debug lines).
Is there an easy solution my end, given that I can not change the asset I want to use?
Note that I have also seen this on a smaller test scene where I had lots of tilted cubes at the edge of a path and a “ceiling” 3 units above the floor. An AI was caught by the tilted cube ray hit and ended up on the ceiling (which had no navmesh).