[Solved] I broke my eGPU and it done broke my gall-dang heart.
After several months of flawless and predictable behavior, my eGPU (Razer CoreX w/ NVIDIA 1080ti) broke off the relationship with my 2018 15" MacBook Pro w/ Touch Bar. I imagine I updated something somewhere and have driven a wedge between these two former lovebirds. After fucking around in Terminal for hours trying to troubleshoot(which is well beyond my skillset), then separately trying each solution for my setup (EFI/PurgeWrangler/set eGPU), I'm at a loss on next steps. I guess my next move is wiping the system, clean install of High Sierra, then trying EFI? Am I missing something?
High Sierra 10.13.6
CUDA Driver Version: 418.105
NVIDIA Web Driver: 318.104.22.168.40.124
Pending: Add my system information and expected eGPU configuration to my signature to give context to my posts
You can boot into Recovery mode to reinstall 10.13.6 on top of your existing macOS so that the system files are reset. Once that's done, you can try one of the macOS eGPU solutions again. Also take a look at @Mac_editor's troubleshooting guide.