I'm getting around with a strange behavior using Geoprocessor managed class inside a .NET SOE for ArcGIS Server 10.3.
Main subject of SOE is to project an input FeatureClass from WGS84 to UTM32 but it seems to work just first time I call this specific method but it doesn't work for the other coming request.
Unfortunally I've no error and the tool seems to run correctly, but the new generated FeatureClass is simple empty.
If I stop and restart che SOE service's and call the method again it works but just for one time.
Inside this method there are a couple of other GP tool (thiessen polygon and copy feature), but only the Project Tool fails from the second run!!
I've got the same issue using che NON managed Geoprocessing class (using IGeoProcessor interface) but no luck again.