Can't turn off light on new Razor Basilisk mouse

I recently purchased the Razor Basilisk mouse, which is nothing short of brilliant... but when my PC shuts down the light remains on. Does anyone know how to fix this? I have synapse installed, and the mouse lighting is set to turn off when display is off or when idle - which works perfectly, but when I turn off my pc the keyboard (also Razor) and mouse lights turn off, then 5s later the mouse light turns on again. If I unplug the mouse and plug it back in after shutdown the light stays off, but next time I use my PC the light stays on after shutdown. I have also tried switching the USB ports in case there was phantom power, but nothing turns the light off. I'd really appreciate some help if anyone has any ideas...