Lit virtualiser is not rendering item with lit element with version 2.4.0 but rendering with 3.2.0

Question

While using these

"dependencies": {
    "@lit-labs/virtualizer": "2.0.12",
    "lit-element": "2.4.0"
  },

and this render method

render() {
    return html`
      <lit-virtualizer
        .scrollTarget=${window}
        .items=${data}
        .renderItem=${(contact) => html` <div><b>${contact.name}</b></div> `}
      >
      </lit-virtualizer>
    `;
  }

getting result as

[object Object][object Object][object Object][object Object][object Object][object Object][object Object][object Object][object Object][object Object][object Object][object Object][object Object][object Object]

this works well with the following

 "dependencies": {
    "@lit-labs/virtualizer": "2.0.12",
    "lit-element": "3.2.0"
  },

Tried downgrading lit-element but that didnt work