I can add something to this thread as I've had exactly the same regarding memory slot three and corsair vengeance.
This has been confirmed as a Corsair issue by Gigabyte as per following thread via Gigabyte support
Hello,
Our team has confirms that the address conflicts. We have contact and ask CORSAIR to modify their software part.
You are requested to raise a support ticket to Corsair and report this issue as well.
We have escalate this issue to our software team in HQ Taipei and they already contact and work with Corsair to amend their iCue software. Sorry but we do not have a case reference per requested.
I raised a ticket myself for the issue with icue as it's only Corsair's software which is not seeing slot 3 on the Aero board, the memory is operating fine and other brands of RGB work fine.
So far no response other than thanks for the feedback and icue 4.16.194 does not fix the issue
If more users log the problem with Corsair then more chance of them actually fixing this issue.