When creating a creating a Webmap there is the following options under Settings --> Offline --> Advanced Options
Use a tile package for the offline basemap.
Define what mobile devices use for a basemap.
Device will use the basemap defined by the web map.
Device will use a tile package it already has.
Enter the filename of the package on your device.
However when I enter a package that has been sideload onto my device and go offline it still downloads the webmap???
Is there something else I need to do?