I'm on 1.21.1, and i even tried the src folder thing and it doesn't work. using 7.7.2
heres something i found in the devlogs
In case nothing shows up in VSCode, check that:
Many JSON files started with "probe" in the .vscode folder are under your .minecraft folder.
There is a "probe" folder under the KubeJS folder, and many files ending with ".d.ts" are in the folder.
All ".d.ts" files don't have syntax errors indicated by VSCode.
I found none of those in my vscode.