Well, here's a good one for you - Using A-frame Extras Pathfinding and working on building patrolling agents using waypoints. HOWEVER, the characters (especially the random patrol lady) fall through the navmesh and get stuck. The guy is following the waypoints in order and occasionally will miss the navmesh: https://glitch.com/edit/#!/pointy-helix-macaroon
I made the navmesh and waypoints visible for reference.
I tried cleaning up the Navmesh a bit (removed 'rounded' corners) but if anything, it made it worse. Is it a bounding box issue?