找到国外大神的解决思路和方法了I managed to fix the problem. The solution is omitting the Mystic Light internal USB device from the USB map.I mapped the USB ports (https://www.tonymacx86.com/threads/the-new-beginners-guide-to-usb-port-configuration.286553/) and removed - among others - PRT3 within the XHC0 controller, which held a device named "Pro Carbon", because I could not find its purpose. After removing said port, the motherboard's RGB started to work as expected. Therefore it think this problem was related to USB mapping; the mentioned entry is probably the motherboard's RGB.