vscode-solidity: Problems With Solhint Plugins

I’m trying to use the rules on a custom solhint plugin by changing the .solhint.json configuration file. The rules themselves work as I can lint the file manually using the terminal and I get the expected errors, but I cannot manage to make the Solidity plugin itself detect these custom rules.

I have changed the settings to explicitly use solhint as per the documentation i.e

"solidity.linter": "solhint",
"solidity.solhintRules": {
  "avoid-sha3": "warn"
}

And I have changed the .solhint.json as per the Solhint docs too.

Any idea of what I am doing wrong?