I have disabled $wgMediaViewerUseThumbnailGuessing and edited resources/mmv/provider/mmv.provider.Image.js and changed to imagePreloadingSupported to always return false. But still facing issue in opening image with Private namespace.
Media wiki version - 1.35.3,
MultimediaViewer version - MultimediaViewer-REL1_35-0e0e0f7.tar.gz