@N1XZ 

Thanks for the configuration screenshot.

I can explain this: as per the settings on the C80, there is no device in the high priority, which results in the upload/download bandwidth setting actually doesn't take effect, that's why you can still get the full speed.

You need to choose at least one device in the high priority, leave others' priority off, let's call the device with high priority device A. Device A will always get unlimited speed with high priority, all the others will be limited by this 15 Mbps upload and 17 Mbps download, they cannot get more than this.

Please note that the current QoS setting on the C80 will not give you the option to limit the bandwidth of every device in the network, while we already have the plan to add the bandwidth control feature on it, you need to wait patiently for that.

I hope this make sense. Good day.