Network Speedlimit not working correctly

[RankoSaotome]

Hello.

I use a WAN/Internet connection wich I share with some others.
When NBP starts to download it grabs all the Network speed and the others get very slow Internet.
So I tried to configure NBP so, that it slows down the networkusage at the times the others are also using Internet.
But the NBP slows down to almost 0 bits/s. Some time after several minutes it goes a little up to (in example) 3 Mbit/s download speed, but that is far under the set limit.
What I did:
NBP /Options /Settings /Network /Speed /around 170Mbps 21 MBps.
NBP /Options /Settings /Schedular / <several hours every day set to slow>
As soon as I deactivate the speedlimitation (in the statusbar I can switch the limiter for several seconds until the schedular kicks in again), NBP needs some seconds but then it grabs again the complete downloadspeed.

How can I get NBP to slow to the set/desired Limit and not very far below?

And why is the max limit in NBP only 200Mbit/s and not higher?

(yes all together it is a fast WAN/Internet with around more then 200MBit/s down.)

NBP 6.81 Build 5080