Full zoom out on 1-page pdf not working Completed

When I load a 1-page pdf from an asset I initially get it fit on the screen. If I then zoom in and then try to zoom it all out I can't zoom out until its entire width fits the screen, but it only zooms out up until the entire height fills the screen (because its height/width ratio is less that that of the pdfviewer/screen), i.e. it doesn't know how to add the gray outside the page gradually by zooming out until the entire width is visible. However, I discovered if I double-tap it can zoom out to it's initial form (entire width visible, with gray areas above and below the page).

I believe the expected behavior would be that you can zoom out until the entire width is visible.

Here is how I initialize the widget:

SfPdfViewer.asset(
 "assets/music_sheets/CB1.pdf",
  maxZoomLevel: 5,
  enableHyperlinkNavigation: false,
  enableTextSelection: false,
  interactionMode: PdfInteractionMode.pan,
));