If you are referring to https://rog.asus.com/forum/showthread.php?100212-ROG-Strix-Z370-G-WIFI-AC-4-Dimms-Slot-Problem/page2 you stated that "I don't have that kit, sorry"
Please note that I am talking about CMR32GX4M4C3466C16
Someone was reporting similar issues with the 16GB kits, too. I tested all three variants that Corsair makes and they were all stable on the board. With that being the case, you're likely going to need to tune things yourself.
Raja@ASUS - Are you talking about them being stable at 3466Mhz??
If so how about shoot some of those tweaking numbers around!
OK, so they ran at 3200Mhz just by using XMP?
Great! So even though your (ASUS's) QVL don't have them listed as XMP enabled some of the memory will still run using the XMP mode at the higher speeds?
That's good news. I wonder why the testers didn't try xmp mode on all the memory they tested and then labeled them with it?
Especially when some of your techs are telling people that if it isn't listed as XMP in the QVL then ya'll don't guarantee it will. It sure would make a better selling point for the motherboard(s) I know my G-Skills sure don't do that at 3466.
@Raja, when you said "However, on our side, said kits are stable", I guess you were using 1401 without telling us.