How about a different router, DLink has several DIR series routers that work well for gaming. DIR-857, 835, 825, 657, 655, 645. If you can find a good working used DGL-4500, was the best gaming routers ever. Not made any more so highly saught after. Some left on fleabay and amazone
Over all this seems to be a NG router issue and best to post in the NG forums for that.