I have exactly the same problem here and I cant seem to fix it. When I change the header for the Kraken x72 to the AIO header, the post shows CPU fan error.
I believe I am on the latest BIOS.
For me, the problem was Cabinet top cover blocking Cooler Master ML360R RGB fans. Once I removed that piece, temperatures fell from 95C to 75C under heavy load.
If you use corsair Link then set your fans to performance
I just bought Tuf Gaming X570-Plus (Wi-fi) board & a ryzen 9 3950X. My temps went nuts on idle temps were 75+ to 90C+
So i re sit the processor re applied MX-4 thermal compound 5 times the heat went nuts.
So as a last ditch attempt to not hit my PC with a sledgehammer. I went into Corsair Link software and set my temps to performance setting from Quiet turbo performance. And soon as I did this my temps fell down to 30C idles 56C under load I set my processor to basic defaults 3500 clock it has been ruining stable ever since Crossing fingers LOL.
Using Corsair H110i GTX water cooler 280 Rad.
I hope this helps people cause i was very angry at the temps I could have easily broke a brand new system.
I also went into BIOS and made my profile as CPU max settings for fan since it was a water cooler and you do hear the fans but I can live with that rather than not having a PC.
For me it looks like a Programs fault. I don't know what would happen if I uninstalled the Link software and just used BIOS it's ruining the now so not going to take that chance.
Manual pictorials very small unless you use a magnifying glass or have 20 20 eyesight you can not read it I wish Asus screw the nut for a change that not every user has perfect eyesight.
Using Windows 10 64bit version 16gb 3200 mem GSKILL