STR:
  - Go to https://mozilla.github.io/pdf.js/web/viewer.html
  - Click on "Open File" and open a pdf

The `Download` button and the `Current view` one just disappear.
I can reproduce this bug with Firefox nightly, Chrome stable and Epiphany on debian.
const location = evt.location,
    store = PDFViewerApplication.store;
  if (store && PDFViewerApplication.isInitialViewSet) {
    store
      .setMultiple({
        page: location.pageNumber,
        zoom: location.scale,
        scrollLeft: location.left,
        scrollTop: location.top,
        rotation: location.rotation,
      })
      .catch(function () {
        
      });
  }
  const href = PDFViewerApplication.pdfLinkService.getAnchorUrl(
    location.pdfOpenParams
  );
  PDFViewerApplication.appConfig.toolbar.viewBookmark.href = href;
  PDFViewerApplication.appConfig.secondaryToolbar.viewBookmarkButton.href =
    href;
  
  const currentPage = PDFViewerApplication.pdfViewer.getPageView(
     PDFViewerApplication.page - 1
  );
  const loading = currentPage?.renderingState !== RenderingStates.FINISHED;
  PDFViewerApplication.toolbar.updateLoadingIndicatorState(loading);
}
function webViewerScrollModeChanged(evt) {