I'm sorry, but did you not understand the solution offered by Apple? You have to log in to your Mac as Admin, the Root User, Master Account or whatever Apple calls the one user that can make system changes. I don't use a Mac so I haven't the terminology. That User (what ever they call it) can execute commands via the Terminal (command line interface) that can make permanent changes across the entire system. The change you are looking to make is:

defaults write com.apple.desktopservices DSDontWriteNetworkStores -bool TRUE

Exit the Master account. Reboot and go back to your normal user account.

As the Root user adding the following in the terminal will return the sort behaviour as High Sierra:

defaults write com.apple.desktopservices UseBareEnumeration -bool FALSE