VSCode ignoring indentation settings in Haskell

I've disabled every extension not related to Haskell, so all I have left is the Haskell extension (just called Haskell) and Haskell Syntax Highlighting.

My settings are here

{
    "haskell.manageHLS": "GHCup",
    "editor.formatOnSave": true,
    "editor.formatOnPaste": true,
    "[haskell]": {
        "editor.defaultFormatter": "haskell.haskell",
        "editor.tabSize": 4,
        "editor.insertSpaces": true,
        "editor.detectIndentation": false
    },
    "editor.detectIndentation": false
}

In the bottom right of my VSCode it says "Spaces: 4" and the language mode is set as Haskell. When I try to select the default formatter it's listed as the Haskell extension. In the extension settings for Haskell it doesn't say anything about indentation, so I'd assume it would just use the settings above.

Yet when I save it changes all my indentation to be 2 spaces, instead of 4.

Why is it doing this, and how do I fix it?