your windows might have other software running as router . that while netcut not forwarding the packets, the other software does. are you using latest version? 1.0.3 disable remote routing service, it does not cover all but help some. as there is not possible or intend we know what other software running on your PC.
like other developing process, we spend quite of effort design,develop,test and main the software, the time and hardware/online service with a cost. purchase service is much appreciated.