Apparently it happens with ABPaths as well as FloodPaths. Also, I was wrong in my previous post - the funnel modifier helps but it does not fix it. You and I are having the same problem - my post is here: https://forum.arongranberg.com/t/paths-dont-take-the-direct-route. I have narrowed it down to being an issue with the navmesh cutter, but we will have to wait for help from someone else to figure out how to fix it.