Having the exact same issue for World of Warcraft Classic
Using a 2019 iMac Pro running bootcamp
Fresh 19041.329 Windows 10 Home build
Tried running admin, reinstalling bnet and app data/win10, local admin account, firewall/security disabled and exceptions.
I ran the solution from here, which got me to the prompt screen to install on harddrive location, but now Im just stuck in waiting… mode
After relaunch of BNet I get the Blizzard Agent went to sleep. Attempting to wake it up…
Really frustrating as I’m using this work computer as my primary now I’m WFH.