Graphics card problems since updating to macOS 14.4

Hello,

I am posting this because I've been having problems with my hackintosh since upgrading to macOS Sonoma 14.4... Before this update, no problem, everything worked perfectly. I could easily do video editing and occasionally play graphics-intensive games. But since the update, I can't do the same: when I launch greedy operations such as exporting a video to Premiere Pro or simply a game like Farming Simulator, I have about ten minutes left before I systematically get a black screen, the graphics card fans making an abnormally lot of noise. At this point I'm forced to restart and I lose the work in progress. Perhaps it's an H264 graphics acceleration problem?

As my Sapphire Pulse Radeon RX580 8G graphics card is (or at least was) natively supported on macOS, I've never given much thought to graphics problems and so need some help...

If it helps, I'm now running macOS Sonoma 14.6.1 with Opencore Legacy Patcher (OCLP) patches. I can provide my EFI file and/or logs if required.

Thank you very much for your help.

PS: here are some extra infos on my config:
i5-9600k Coffee Lake, 16G RAM DDR4, Sapphire Pulse Radeon RX580 8G