As stated in the question, the issue has been observed only on Windows 10 devices when trying to go offline.
The tested maps work perfectly with Androïd devices: I download the map for offline mode and the existing feature layers appear normally on the basemap.
I do exactly the same with Windows 10 devices: only the basemap is displayed on the offline map, I cannnot see any feature (and neither edit them). The issues seems however to concern only the display: the feature layers are in the content tab, and I can add new features normally. In the creation mode, I can see and locate a feature, but it will disappear after sending.
The newly created features are apparently stored because they will appear on the map in ArcGIS Online after synchronizing.
I tried with several maps and configuration, using simple sync-enabled features layers (Arcgis Online), all the parameters are correctly set for offline usage (as it works on Android devices).
We are using Windows 10 Pro, version 1607 on Panasonic Tablet and Lenovo PC. Same issue with both devices.
Help will be greatly appreciated !