Multisig Address Build Error

Hello all,

I am trying to build a muiltsig address using shelley simple scripts (cardano-node/simple-scripts.md at master · input-output-hk/cardano-node · GitHub)

The purpose of this scheme is to have a regular 2-of-2 multisig address backed by a third emergency key that is only valid after a certain slot number.

Here is my script syntax in json form:

{
  "type": "any",
  "scripts":
  [
    {
      "type": "all",
      "scripts":
      [
        {
          "type": "sig",
          "KeyHash": "0d4db33028a10e797670509faf8f8d0d42e35c1d6e78cb5d78403f2d"
        },
        {
          "type": "sig",
          "KeyHash": "69ad5d0ba81fbb859d613b776564596de660d88d032a923347646663"
        }
      ]
    },
    {
      "type": "all",
      "scripts":
      [
        {
          "type": "after",
          "slot": 40500000
        },
        {
          "type": "sig",
          "KeyHash": "4b263032e57de4cd8a385bc19dbd12ed54499c7d1d483134e616e2dc"
        }
      ]
    }
  ]
}

However, when building the script address using [ cardano-cli address build --payment-script-file <multisig.json> --testnet 1097911063 --out-file multisig.addr ] , I get the following error:

Command failed: address build  Error: multitest/multisig.json: Syntax error in script: Error in $: "atLeast" script value not found

Am I doing something wrong here or is this a novel bug?