If you can create a repeatable scenario, I would suggest that you set up a GoPro and record the circumstances of the system failing to detect the motorcycle in front. (Also record the circumstances of the system correctly detecting either the motorcycle or some other vehicle in front.) Find out who you should send the video to at the vehicle manufacturer, and also report it to Transport Canada here and to NHTSA in the USA. Given the potential liability, and provided that you find the right people to notify of this issue, they ought to be very interested in this.
All such systems have technical limitations, but a vehicle (of any legally-registered-for-the-road type) directly in its path and travelling steadily at a comparable speed should not be one of them.
My van has the back-up warning system, and it beeps at curbs, signs, bushes, etc.
The lane-departure warning systems have technical limitations because of the short range of the sensor. It cannot be a long range sensor because of potential interference and false-tripping issues. If you are sitting next the vehicle in traffic and gradually moving past it, they should work. They will NOT detect a vehicle approaching in the adjacent lane at a speed 100 km/h faster, until it's too late!
The good thing about the VW Group buying Ducati, and Mercedes buying MV Agusta, and BMW and Honda already making motorcycles, is that there is a substantial base of auto manufacturers who have an interest in their systems working across vehicle types.