The tank Vent Valve is fitted to the fuel tank to stop fuel vapour venting to the atmosphere when the bike ignition is off & it is pulsed on/off when the bike is running. It was a US only device on older models, not sure whether it is fitted on the latest EU models
Look at the throttle bodies or air box, you should see a tube running back to the fuel tank & the valve, check that it is plugged in properly, also check your Repair Manual, it should show where the valve is fitted on your model.