that's because these Samsung browsers are a mix of the new Chrome browser and the old Android browser.
That browser itself is basically an Chrome browser and identities itself also as Chrome, but it is using a different page-scaling than Chrome (the old Android browsers and the Chrome browsers have a different page-scale support).
This problem will be fixed in the next krpano release - there the viewer will automatically detect if the current page-scale is valid for an Android Chrome browser and if not, it will behave accordingly to provide a correct scaling.