Freeze after i9-9900k + 64Go upgrade !!

I just upgraded my setup.

From a i5-9600kf, 32Go DDR4 3200 to i9-9900k, 64Go DDR4 64Go.

My motherboard is still the same : MSI Z390 MAG Tomahawk.
My SSD is a Samsung EVO 970 1To M.2

Graphics card : RX 5600 XT.

Everything worked fine before the update.
Big Sur was 100% functionnal.

But now, while Win 10 is flying with the i9, I can't boot macOS.

I tried a full new install (new USB) with a full OC 0.6.5 config, but nothing works.

I'll attach my config.plist, in case someone has an advice .....

Freeze there :(