Start counting collection elements at 1 not 0

                        <Listing :items="payload" :loading="loading" @scroll="onScroll">

                            <template v-slot:item="{ item }">

                                <ContentItem

                                    :id="item.element_index"

                                    :id="item.element_index + 1"

                                    :item="item.object"

                                    :name="item.element_identifier"

                                    :expand-dataset="isExpanded(item)"