Before revision:  Our algorithm is based on the earlier algorithm for k-Disjonit Paths with Congestion-c[ IPL 2019, MFCS 2016 ], but we significantly simplify their argument.
After revision:  Using the techniques for DAGs, we show the problem is solvable in time f(k) n^{O(k) is based on the earlier algorithm for k-Disjonit Paths with Congestion-c[ IPL 2019, MFCS 2016 ], but we significantly simplify their argument.