I have the same problem :(
Could you take a look at the other reply to see if yours is set up in a similar way? KBonk has settings for two different ports; if they're both set to the same number, it'll cause issues when two things try to use the same port at the same time.
If the "Browser Source Port" and "VTube Studio Port" in KBonk's settings are the same, please change the Browser Source Port to a slightly different number!