Lately I accidentally resetted my Developer options on my BlackBerry KeyOne. So after trying to get them back to where they were, I was stuck with a problem :
Everytime I tried to setup wireless debugging ( Like explained here : How to enable wireless debugging ) the device was being disconnected upon unplugging the usb, which of course defeats the purpose of wireless debugging!
So finally, I found the issue :
The BlackBerry KeyOne ( and some other android devices ) support a so called "Charging Only"-Mode, and a Data-Transfer mode. In the developer options, one can enable USB Debugging either only if in Data-Mode, or also if in Charging mode..
Now, don't ask me why, but if you have charging-mode debugging disabled, well the wifi debugging doesn't work! So to get back to wifi debugging, simply allow debugging in Charging mode and you are back on track again!