lightning-navigation stopped working post summer 20 release

We are using lightning navigation module in Lightning Web Component to navigate to a page. This was working fine before summer’20 Salesforce release but it stopped working post release.

   Reset(event) {
        this[NavigationMixin.Navigate]({
            type: 'standard__navItemPage',
            attributes: {
                apiName: 'Product_Creation',
            },
        });
    }

Anybody else facing the same issue? Or something changes in navigation module which i am not aware of?