IOConsoleUsers: gIOScreenLockState... after upgrading from a working Catalina installation to Big Sur with OpenCore

I've already read Dortania's guide. Having tried setting "-igfxmlr npci=0x2000" in boot argument, setting up framebuffer-patch (unnecessary as I've already modified DVMT pre-allocated), and re-enabling CSM. I even tried wiping out the full disk and do a clean install but none of these works :(

Screenshot:

Processing img xjr133syv0g61...

CPU: i7-6700

GPU: HD 530

SMBIOS model: iMac 17, 1