Hi Alexey,
this seem to be the discovery:
Microsoft.SystemCenter.Apm.Web.IIS10.Endpoints.Group.DiscoveryRule (Discovery)
not quite sure though why it does not work for this particukar .NET app. Are there any errors in the event logs on the server, hosting it? Can you please check that.
The other tzîng is that you need to wait at öeast 4 hours for the dioscvery to kick in. If this is the case and 4 hours have passed, please try to find some clues on the agent side in the Operations Manager event logs.
Regards,
Stoyan