Physics.SimulateWaitForJobGroupID

I keep getting huge spikes in my game from the following hierarchy: Playerloop.Fixedupdate.Physicsfixedupdate.Physics.Simulate.WaitForJobGroupIdIdle. Anybody know that is? It happens at a point in my game where a lot of NavMesh Agents are moving around, which may cause a spike in physics collisions. Is this expected behavior if you have too many physics interactions?