How keyboard's drivers work on linux

I recently bought a new keyboard, it was cheap and of an unknown brand but i wasn't particularly worried. I found out that on linux pressing __shift, super, left-ctrl or left-alt with this keyboard__ made no difference, it always take it __as shift__. I made some researches and it turns out the problem is the chipset used by the keyboard. I read that the only way to solve the problem is to write a driver for the keyboard, but, while working on it i found out that running __sudo modprobe usbmon__ and then __opening wireshark as sudo__, unexpectedly __fixes the problem__... someone knows why this happen? and if there is a simpler way to trigger this change? to be more specific: - i'm on xubuntu 18.04 - dmyco is the brand of the keyboard - the result of lsusb is >> Bus 001 Device 004: ID 1c4f:0056 SiGma Micro