VSE should have two network connection(internal and External). Are we sure we are looking at the fenced Edge ? Log into vShield manager and check the interfaces for the edge.
You can try running debugging on Fence Edge external interface-> IP of Next Hop(In this case Routed network Edge Internal) and check if translation is happening when you try to communicate with external network.Basically you need to do a Hop By Hop check . Or you could try connecting Fenced App directly to External Network and confirm Fence Mode is working.