Nested attributes not working on 6.4 version

[himanshudhakan]

I am facing an issue with storing nested attributes only for version 6.4 and later, But it's working fine on older versions. code as below.

attributes are not saving after updating the page.

let attributes = {
	styleAtts: {
		titleStyle: {
			fontSize: '12px',
		}
	}
};

let tempStyleAtts = attributes.styleAtts;
tempStyleAtts.titleStyle.fontSize = '15px';

props.setAttributes( {styleAtts: tempStyleAtts} );