I just posted a similar issue to this. One of my 8 led series fan #5 on my capellix elite 150i just stops spinning when icue software boots up. When I exit the icue software it starts spinning again. When I am on the software it allows me to control the rgb on it but refused to show up on the cooling tab. It shows fan 1,2,3,4, (skips 5),6. I reverted back to 4.31 on a thread I found on here but that does not seem to fix the issue.