Congrats, you just found that RGB abd aRGB are different. RGB is analog, working of 12v and has sets of 3LEDs, one for each color with 4 vires (+12v and 3x -12v). ARGB is digitally controlled, Each LED can produce 3 colors and works with 3 wires. (+5v. -5v and a control wire as third). So completely not compatible with each other.Fixed it by plugging it into the "aRGB" motherboard plug. This only has 3 pins sticking out. Also, I had to press it in with some resistance. Now it works. Thank you everyone!