RT-AC66U Qos not working properly

So I have the RT-AC66U, for some reason I can't use my 240mb/s download if Qos is enable. The max I can get is 110mb/s. The upload works fine. I just have issue with the download. I picked manual Bandwidth Limiter and clicked on my pc for testing. Even though it's set for 240 for my download it doesn't go near that, just stays at 110mb/s. It does go lower, if I set it for 50mb/s then it will stay at 50. If I turn off Qos then I get my 240mb/s. Is it time for a new router?
Thanks