Why custom AI move without Navmesh?

My AI is a SimpleCubeMesh Pawn with custom Move (ForwardVector +500 etc)
But it goes without navmesh … I have a controller to move my AI, besides my movements are on the BP_AI_Controller not in BP_AI__Pawn. I tested different configuration with navDefault, recast without success … I have to miss something quite simple, I think!
My question is, how do you force my AI to use the NavMeshBoundsVolume?