PrimeNg dinamyc MegaMenu doesn't appear

Question

I'm creating a MegaMenu dynamically, starting from a map:

this.menuItems = new Array<MegaMenuItem>();
this.map.forEach((value: Map<string, any[]>, key: string) => {
     const catArray: Array<Array<any>> = new Array<Array<any>>();
     value.forEach((inValue: any[], inKey: string) => {
         const catMenu = {
             label: inKey,
             items: inValue
         };
         catArray.push([catMenu]);
     });
     const moduleMenuItem: any = new Object();
     moduleMenuItem.label = key;
     moduleMenuItem.items = catArray;
     this.menuItems.push(moduleMenuItem);
 });

In HTML:

<p-megaMenu [model]="menuItems"></p-megaMenu>

The MegaMenu is correctly configured. If I test it with the example of the PrimeNg site it works fine. It seems like the object menuItems is not properly created but I can't understand where I'm wrong.