Autonomous trucking technology company TuSimple and truck manufacturer Navistar have scrapped their deal to co-develop self-driving trucks, the companies said Monday. The move to end the partnership comes less than a month after Cheng Lu returned to his role as CEO of TuSimple after previously being ousted. The return of Lu came days after the company fired his predecessor and TuSimple’s co-founder Xiaodi Hou following an internal probe that showed certain employees having ties and sharing information with Hydron, a China-backed hydrogen-powered trucking company. Part of the reason TuSimple and Navistar ended their deal was because the former “needs to…