MongoDb returns only 450 documents out 871?

Question

I have an old Angular App written in 2015. Once number of documents grown - I start to see that webapp does not show all documents, but only part. So in order to add new document I need to remove an old one.

Can anyone help me with this enigma?

                    return $q(function (resolve, reject) {
                        $http.get("/mongo-articles").then(function (response) {
                            setPublicNewsLive(response.data);
                            resolve();
                        })
                    });
                }