The element I am attempting to engage with utilizes the ng-sortable attribute and consists of a few draggable and sort-able divs.

await viewTransaction.getEl('div#dragdrop-boundary').sendKeys(protractor.Key.ARROW_DOWN);

Failed: element not interactable

In this instance, the element is visible. Is it possible that only specific elements such as dropdowns can be affected by sendKeys in this manner?

Referencing the Documentation, which explicitly mentions a WebElement.

I am primarily questioning whether only certain WebElements are capable of being manipulated in particular ways like using protractor.Key.ARROW_DOWN?

This is some of the markup:

Note: Names of classes and variables have been changed for confidentiality purposes.

<div ng-show="sortMode.sorting" id="dragdrop-boundary" class="sortMode-high">
    <div ng-if="Transaction &amp;&amp; Transaction.TransactionId" ng-repeat="Section in Sections" class="ng-scope">
        <div ng-hide="'PICKLIST' === Section.SectionId" class="lineItem-title ng-binding">Rental</div>
            <div data-ng-model="SortableLineItems[Section.SectionId]" data-as-sortable="sortableOptions" class="ng-pristine ng-untouched ng-valid ng-scope ng-not-empty">
                <div data-as-sortable-item="" data-ng-repeat="LineItem in SortableLineItems[Section.SectionId]" class="ng-scope as-sortable-item">
                    <div as-sortable-item-handle="" class="sortMode-existing-lineitems sortMode-row sortMode-outerRow sortMode-item-enable                                             sortMode-selected" ng-class="arbitrary:LineItem.TransactionType=='SALEFEE','kit-component':LineItem.IsKitComponent,'damage-waiver':LineItem.TransactionType=='DAMAGEWAIVER',discount:!LineItem.ItemId &amp;&amp; LineItem.ItemKey.includes('Discount')}">
                        <div class="sortMode-icon-container">
                            <button class="btn-default btn btn-xs action-btn-delete ng-scope" ng-if="LineItem.ItemId && LineItem.LineItemId" disabled="">
                                <span class="roro-icon roro-icon-cancel"></span>
                            </button>
                        </div>
                        <div class="sortMode-cell sortMode-item-name ng-binding">Wagon</div>
                        <div class="sortMode-cell sortMode-item-key ng-binding ng-scope" ng-if="LineItem.HasItemKey">ITEM-3</div>
                        <div class="sortMode-cell sortMode-amount-per-item ng-binding">$30.00</div>
                        <div class="sortMode-cell sortMode-quantity ng-binding">1</div>
                        <div class="sortMode-cell sortMode-amount-text ng-binding">$30.00</div>
                        <div class="sortMode-cell sortMode-tax-free-text ng-binding">T</div>
                        <div class="clearfix line-item-instances ng-scope" ng-if="LineItem.ItemSerialized && & !RemovingItem[LineItem.LineItemId]">
                        <div ng-class="{'padding-none' : !subItemPopup[$index].active}" class="padding-none">
                            <div class="line-item-cards">
                                <div class="line-item-card tbd-card ng-scope" ng-if="LineItem.CountUnassigned"><div>
                                                        <span translate="TBD" class="ng-scope"><p>TBD</p>
                                                    </div>
                                                </div>

                                            </div>
                                        </div>
                                    </div>
                                </div>
                            </div>
                        </div>
                    </div>
                    <div ng-if="Transaction && Transaction.TransactionId" ng-repeat="Section in Sections" class="ng-scope">
                        <div ng-hide="'PICKLIST' === Section.SectionId" class="lineItem-title ng-binding">Damage Waiver<</div>
                            <div data-ng-model="SortableLineItems[Section.SectionId]" data-as-sortable="sortableOptions" class="ng-pristine ng-untouched ng-valid ng-scope ng-not-empty">
                                <div data-as-sortable-item="" data-ng-repeat="LineItem in SortableLineItems[Section.SectionId]" class="ng-scope as-sortable-item">
                                    <div as-sortable-item-handle="" class="sortMode-existing-lineitems sortMode-row sortMode-outerRow
                                        sortMode-item-enable
                                        sortMode-unselected" ng-class="{arbitrary:LineItem.TransactionType=='SALEFEE','kit-component':LineItem.IsKitComponent,'damage-waiver':LineItem.TransactionType=='DAMAGEWAIVER',discount:!LineItem.ItemId && & LineItem.ItemKey.includes('Discount')}">

                                        <div class="sortMode-icon-container">

                                            <button class="btn-default btn btn-xs action-btn-edit ng-scope" ng-if="LineItem.TransactionType == 'DAMAGEWAIVER'" disabled="">
                                                <span class="roro-icon roro-icon-edit"></span>
                                            </button>

                                        </div>
                                        <div class="sortMode-cell sortMode-item-name ng-binding">Damage Waiver (10%)</div>
                                       <div class="sortMode-cell sortMode-item-key ng-binding ng-scope" ng-if="LineItem.HasItemKey">N/A<div>

                                       <div class="sortMode-cell sortMode-amount-per-item ng-binding">$3.00</div>
                                           <div class="sortMode-cell sortMode-quantity ng-binding">1</div>
                                               <div class="sortMode-cell sortMode-amount-text ng-binding">$3.00</div>
                                                   <div class="sortMode-cell sortMode-tax-free-text ng-binding">T</div>
                                </div>
                            </div>
                        </div>
                    </div>
                </div>