Hello,
I have a similar problem.
I have 3 fans and the first fan works fine but the other two have some issues. When I turn on my pc the RGB is off. A few moments later it starts working with some glitches. Then i go to Corsair Services, as JimmyRappit told, and press Stop 1-2 times. And after that the fans start work properly. This procedure must be done every time that I turn my pc on and it takes me about 10 minutes. I have tried everything that is written on this forum but nothing has solved my problem completely. Do you have any solution???