In the image below the orange character was facing my player when alerted. They were then tasked to do a AI Move To, but before they did that they started running out of the nav mesh hole they are stood in. This hole only exists because the nav mesh is generated around their location (see the 2nd image).
Fixed - the two spheres on the character’s hands had BlockAll collision type, causing holes in the navmesh. Setting these (and all other components to be safe) to CharacterMesh preset fixed the issue, though I had to delete the recast and the navmesh bounds, build paths then re-add the navmesh bounds and rebuild the paths to plug the hole up.