so basically my understanding of it is as follows:
on a router, the first device to download and use netcut is the “admin” so if anyone other device has used netcut first on your router then only that device can control the wifi. any device can download netcut and use it to defend against other netcut attempts but other than getting a new router or possibly factory resetting your router and then trying to reinstall and use netcut may be the only 2 options you have. i just got a new pc and netcut is basically useless for me right now.
i could be wrong but this is what i think is happening for both of us. unless there is just something wrong with your install/firewall/computer setup