I faced a similar issue before. The error message I encountered was:

Uncaught Promise > Invalid props for component 'ExistingOrdersDialog': unknown key 'title', unknown key 'orders'

This error only appeared in DEBUG mode. However, I managed to resolve it by adding the necessary props to the component as follows:

export class ExistingOrdersDialog extends Component {

    static components = { Dialog };

    static props = {

        close: Function,

        onAddOrder: Function,

        onSaveOrder: Function,

        title: String,

        orders: Object

    };

}

After including these props, I restarted Odoo and reloaded the page to ensure the new assets were loaded, and the error disappeared. In your case, I recommend checking if the 'currency' prop is defined in the TaxGroupComponent. If not, define it as a String type.

Best regards