Container node is not created

Have a container node and its spec:

const ReferenceNodeSpec: NodeSpec = {
  attrs: { readOnly: { default: true }, objectMetaData: { default: {} } },
  content: 'block+',
  parseDOM: [
    {
      tag: 'reference',
    },
  ],
  toDOM(node) {
    return ['reference', node.attrs, 0];
  },
};

This is available as the first node in the schema:

(schema.spec.nodes as OrderedMap).addToStart('reference', ReferenceNodeSpec);

When I try to insert this node (reference json):

{type:'reference',content:[{type:'paragraph',attrs:{align:'left',color:null,id:'',indent:null,lineSpacing:null,paddingBottom:null,paddingTop:null,contenteditable:null,styleName:'chpara0',objectMetaData:{customEntity:{'http://www.w3.org/1999/02/22-rdf-syntax-ns#type':'DocumentLayout','http://www.w3.org/2000/01/rdf-schema#label':'test-source-doc-planning',},artifacts:[{id:'_Paragraph_test-source-doc-planning-artifact',},],},objectId:'test-source-doc-planning',},content:[{type:'text',marks:[{type:'mark-font-size',attrs:{pt:12,overridden:false},},{type:'mark-font-type',attrs:{name:'Arial',overridden:false},},{type:'strong',attrs:{overridden:true}},],text:'Mission Planning  ',},],},],attrs:{objectMetaData:{readOnly:true,reference:{id:'_reference_206481bc-c9df-4aad-a0d5-b70e58773c02',},},},}

this is what I get: image No reference node, but the content inside that ie paragraph got inserted.

This is the code used to insert using reference json mentioned above:

const tr = view.state.tr.insert(view.state.selection.from, this.schema.nodeFromJSON(json));
    view.dispatch(tr.scrollIntoView());

Please help and educate me, on what I am missing. I am expecting a reference that contains the paragraph. Thanks for considering!

Got it, this was missing:

group: 'block',