No internal nor external display with Windows 10 Bootcamp and RX 560
I have a MSI Gaming RX 560 eGPU connected via Thunderbolt 3 to a 2018 MacBook Pro and Windows 10 (latest download today) in Bootcamp.
In macOS Mojave, I can see the eGPU and get video externally and accelerate internal apps. In Windows 10 however, when the RX 560 eGPU is connected, internal screen just shows the Windows Logo (it giggles a bit) and never shows desktop. I can remote desktop into the Windows, but the internal laptop screen shows the Windows loading logo. Externally, if I connected, shows nothing.
Windows installed the default RX 560 drivers. Could this be a driver issue, or is what I'm trying to do not possible in Windows 10 and this video adapter?
What does Device Manager show for the RX 560 eGPU? When you have an eGPU connected prior to booting, the iGPU would be deactivated which leads to frozen Windows logo. My recommendation is to use DDU to remove the graphics drivers then perform a manual installation of the latest Radeon drivers. If you were to use internal display, try timed hotplug at Windows spinning circles or use automate-eGPU EFI boot loader.
Ugh, it's the dreaded error 12. I did all the steps that don't require boot managers and other invasive techniques, and no success.
I see your build similar to mine:
Perhaps the next version of Windows will make this easier. Works great in macOS with no modifications.
1) Hotplug eGPU, get Error 12
2) Uninstall Device, don't remove files.
Anyway, booting with the eGPU plugged in (or hot-plugging it very soon as @itsage suggests) you should avoid Error 12. If you have Windows 10 Build 1803 or newer this probably won't be better in the future.
I just tried this, and when Windows comes back up, just has a black screen both internally and externally via eGPU. I can remote desktop into it and the only video adapter I see is the eGPU (RX 560) and there's no error 12 any more. The iGPU does not show up in device manager.
This procedure does get rid of the error 12, but doesn't display any images in internal nor external displays with my config.