MP 1,1-5,1 What OpenCore settings for shifting from HD to QHD monitors?

[RickyHunter]

Hi there.
I'm on cMP 4.1-->5.1 with firmware updated and regularly running Catalina last version.
I'm using OpenCore to boot up my machine.
I'm not an expert at all with OC, so I need step by step instructions

I purchased 3xDell U2520D QHD monitors to change my old configuration with 3 monitors (only 1 of them is HD).
I changed the monitors one by one with the machine running and everything was very pleasing and perfectly working.
After turning off the computer, next day I started it and OpenCore was not able to manage the new monitors: black screens.
I'm supposing there are some issues with the config file, but I don't know where to look at and what to modify.

I've replaced the old 0.6 OC version with the new 0.6.9; I started from scratch again and with my old HD monitor everything is ok, but as soon as I attach the new ones, the issue is there.

[UPDATE]
Connections used for monitors: 3x 3 meters display port to display port cables
If I connect only one monitor at startup: everything is fine. I can choose one of the three output indifferently. As soon as the system i ready, I can add the other 2 monitors and they are working.
If I connect two monitors at startup is fine as well.
It seems only the three monitors setup is disturbing the boot up process.

Could anyone assist me? My computer setup is in the signature.
Thanks a lot in advance.

 

[Bmju]

Although you are on actual Mac hardware, I think these instructions may be what you need: https://dortania.github.io/OpenCore-Post-Install/gpu-patching/#intel-igpu-patching

 

[RickyHunter]

Although you are on actual Mac hardware, I think these instructions may be what you need: https://dortania.github.io/OpenCore-Post-Install/gpu-patching/#intel-igpu-patching

I don't think this fit my needs: here they talk about intel gpu, mine is a Radeon, so not intel. Or am I missing anything?

 

[Bmju]

I don't think this fit my needs: here they talk about intel gpu, mine is a Radeon, so not intel. Or am I missing anything?

Ah. I got into OC myself not from the hack community, but just via trying to get Big Sur support on a specific Intel GPU MBP, so is now outside what I've played with personally so far, on my own setups. But a quick Google throws up https://dortania.github.io/GPU-Buyers-Guide/modern-gpus/amd-gpu.html#native-amd-gpus - don't know if it helps?

 

[RickyHunter]

Ah. I got into OC myself not from the hack community, but just via trying to get Big Sur support on a specific Intel GPU MBP, so is now outside what I've played with personally so far, on my own setups. But a quick Google throws up https://dortania.github.io/GPU-Buyers-Guide/modern-gpus/amd-gpu.html#native-amd-gpus - don't know if it helps?

thanks man