The old bandwidth manager from 6.x no longer exists. Now there is a Bandwidth/QoS manager which works differently and it is no easy to make it limit bandwidth. It allows you to allocate priorities with the lowest being 7 and the highest being 1. Any device in band 7 is allowed the full bandwidth if nothing else is using it. However if a device with a higher priority requires some bandwidth, it gets it in preference to a device of priority 7.
It goes on the the thinking "if no one else wants it, why limit the bandwidth of the lowest priority device".