CRS317 Custom Fan Control and Voltage Problem

Hi All, I just got my CRS317 and loving it except the annoying fans. I ordered 2 Noctua NF-A4x20 PWM 12V fans but they won’t spin up after booting up. After some investigation I found that the fan header is outputting about 6V instead of 12V during startup, which the fans did spin.

Is there any way to control the output voltage of the fan header? Or is there some option in routeros that can make the fans run at full speed? I tried different options in the console as shown below but all didn’t work.

set
cpu-overtemp-threshold -- 
fan-mode -- 
fan-on-threshold -- 
fan-switch -- 
use-fan --

I’ll be cool if those nice fans can get to work and have the switch run silently. Any help is much appreciated. Thanks.