My AI stop moving! Pls Help

Thanks, I will give it try. Have you had you a go moving all the mesh and the AI above the grid line for 20 cm. Trust me AI will stop working and I wanted to work above the grid line. is there any chance you can show me how I can do that. The gridline you see often in Unreal engine. here’s the screenshot of it. Pls, do help me make it work above the gridline.