There’s a tiny issue where Netcut won’t limit the user to EXACTLY the amount you set, it just tries to constantly keep them around that limit.
So for example, if I limit someone to 500 kb/s, they may get little 2 ~ 5 second bursts of going a tiny bit above that. For example they might get like a little burst up to 700 kb/s, but Netcut will try to immediately drop them back down to 500 kb/s.
Since you gave them 0 kb/s, they will still get little bursts around 12 kb/s like in your photo. But 12 kb/s is not enough to do anything, it is almost basically like sending ping requests but they aren’t actually connecting to anything.
If you want to block them COMPLETELY from the network, you’ll have to block them in your router or something.
Also if you are a Pro user (its only $1 per month, definitely worth it) check in the Pro options and play with different things like “Cut affect Gateway and User”, etc.