Color Banding through Radeon VII DP

Hello everyone,

I need some help concerning a display problem I am having on my build, I can't seem to find any explanation on my own.

When the interface is blurry, like in launchpad, I have some color banding... (see the image). My screen is supposing enough color depth so it shouldn't be there.

Here's my build :

• CPU: Intel i7-8700K
• GPU: Radeon VII
• RAM: 64gb
• Motherboard/Laptop model: Aorus Z370 gaming 5
• What guide/tool followed: Vanilla
• Monitor : AOC U2777PQU via DP
• Kexts : AppleALC, FakeSMC, IntelMausi, Lilu, USBInjectAll, WhateverGreen

I use iMac18,3 as SMBIOS, iGPU is activated with QuickSync working.

Does someone may have an idea where to look for a solution ? (I already tried with the iGPU desactivated and with iMacPro1,1 SMBIOS)

https://i.redd.it/ohhyu77sr7i31.jpg

https://i.redd.it/hgcarj4sr7i31.jpg