Is there any way that will make the navmesh agent allways in pathpending

Question

I bake my navmesh in runtime with a specific navmesh setting, and sometimes(not always), when I try setdestination to my own agent, the value of pathpending always returns true, resulting in that the agent is waiting for a path to navigate, and just stand there, dont move, for a long time. I'm wondering that is there any way that will make the navmesh agent allways stuck in pathpending, for example, if the scene is far complicated?(there is only one agent in the scene) The picture is the baked navmesh, which seems normal