I am currently trying to use disconnected/offline editing with Collector via editable layers published thru my organizational Portal. I've read thru some of the ESRI docs on preparing data for offline editing and preparing maps for offline editing. My data is registered as versioned; editing capabilities are all checked on when publishing; I add the feature layer to a Portal WebMap; the WebMap has the "use in Collector" checkbox checked on under the settings. However, when I open Collector (Windows Desktop or iPad) and click on the 3-dot ellipsis next to the map, only the "details" option is available. There is no longer a "download area" option. I haven't attempted to do this in maybe 8 months or so but the last time I tried, I had no problem downloading an area for offline editing. The only change I'm aware of is our server and Portal upgrade to 10.8.1 recently.
Any thoughts? Thanks!