Egpu Not detected b on windows 10
If it was regular Windows laptop, I would check Thunderbolt security settings. If the Thunderbolt Security is enabled as "User Authorization", and the eGFX is not authorized, eGPU won't work.
The other suspect is the GPU itself - do you know that it works for sure? I have seen rare cases when a problematic GPU won't get detected, while anything else works fine. Not common, but it does happen.