enableAnnotationAPIs disables the custom text button

Hi,

When I enable the "enableAnnotationAPIs" the add text comment button disappears from the UI. see attached image.

my code is attached

const viewerConfig = {
        // enableAnnotationAPIs: true,
        showLeftHandPanel: true,
        showDownloadPDF: true,
        showPrintPDF: true,
        showPageControls: true,
        dockPageControls: true,
        defaultViewMode: ""
};

$timeout(function () {

        var adobeDCView = new AdobeDC.View({
                clientId: clientID,
                divId: "adobe-dc-view-desktop"
        });

        var previewFilePromise = adobeDCView.previewFile({
                content: {
                        location: {
                                url: $scope.pdfsrc
                        }
                },
                metaData: {
                        fileName: $rootScope.pdfName,
                        id: $rootScope.pdfID
                }
        }, viewerConfig);

        const eventOptions = {
                listenOn: [
                        "ANNOTATION_ADDED",
                        "ANNOTATION_CLICKED",
                        "ANNOTATION_DELETED",
                        "ANNOTATION_UPDATED"
                ]
        };
        const customFlags = {
                showToolsOnTextSelection: true
        };

        // add save functionality here.
        previewFilePromise.then(adobeViewer => {
                adobeViewer.getAnnotationManager().then(annotationManager => {

                        annotationManager.setConfig(customFlags)
                                .then(() => console.log("Success"))
                                .catch(error => console.log(error));

                        annotationManager.registerEventListener(
                                function (event) {
                                        console.log(event.type, event.data)
                                }, eventOptions);


                });
        });

}, 1300);