Thank you, c-attack.
After reviewing what you wrote, I checked again and solved the problem. You were right, but I wanted to proceed without changing the wiring configuration. It turns out that I couldn't control the RGB lights because I selected the wrong fan type in iCue, as shown in the picture I provided. When I selected the 8 LED Fan series, the issue with RGB control was completely resolved. My exhaust fan is indeed the Elite iCue supported version, as you suggested, so I can control both its PWM and RGB lights. Currently, I'm using iCue to control the PWM of the fans through a custom curve on the h100i, and I'm using the Node Pro to control the RGB lights of the other four fans. To synchronize all the RGB lights, I created a setup using "Murals" so that I can control all the RGB lights in sync.
Apart from these, I encountered another problem with not being able to control the h100i and the other fans in PWM mode, and the RGB lights not working. The cause of this issue was an application called HWInfo. To troubleshoot, I selected a static color from the "Hardware Lighting" panel in iCue, and whenever the HWInfo application is running, the system operates in that color, but it switches to the desired RGB setup when I close it. I disabled the monitoring and logging of the Corsair Commander Core through HWInfo, and the problem was completely resolved.
Indeed, as you mentioned, if I had connected all the fans to the 6-slot Commander and selected the correct fan type in iCue, it would have been resolved earlier.