I use Portal for ArcGIS 10.3.1. When I create a map from
My Content the mapextent is not used that I specified under Edit Settings.
It works if I create the map directly from MapViewer.
This is an interesting question. From how it looks, it looks like this is the intended behavior.
When you create a map in the Map Viewer, it uses the default extent that you selected:
For Default Basemap, choose the basemap you want opened when users create a new map with the map viewer. You see the maps in the group you selected for the Basemap Gallery.
The default basemap opens at the default extent you set. To set the default extent to the extent of your currently selected default basemap, click Use map extent as default. To set a different extent, click Choose Extent and enter numerical values or draw the extent. A geocoder is included to help you find a specific place or address.
When you're just adding an item, it will initially go to the extent of that item:
Extent—The extent is the geographic boundary you specify for the item. It is defined using the minimum and maximum x and y coordinates of the area. You can either type these coordinates or draw a box to define the area. The draw option includes a geocoder to help you find a place or address on the map. Portal for ArcGIS updates the coordinates of the extent based on what you draw.
Though, it looks like you may be able to set up some advanced options within Portal and use the "extent service" to configure your extent:
extentService—The service used to update or set the extent of a web map item in the Set Extent dialog box in the portal website. The service must use the WGS 1984 geographic coordinate system with well-known ID (WKID) 4326. The default is http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer.
Do you have a WKID that you can use for this?
I'm not really sure. I'm afraid that I do not know enough about Portal to go any deeper. I wish there was a Portal guru on this board that we could consult with. The best I know would be to tag Jake Skinner