Hi
looks like the client in your log switched to polling @ 00:16:25,168
This is the request that instructs the server to transform the streaming session in a long-polling one:
/lightstreamer/control.js --> LS_session=Sf0d3e570bb765902T1620696&LS_op=force_rebind&LS_cause=sense&LS_unique=2&
the last poll for this session is @ 00:19:36,019. The connection of the last poll is reused @ 00:19:36,020 but then the server didn't receive the "next" request.
So looks like you have two problems with these clients:
first your client cannot stream; probably one of the mentioned firewall/proxy is caching the entire response before forwarding it to the actual client
the second issue is with the request from the client not reaching the server anymore; to verify what happens here you should analyze the traffic both client side and server side; if you see the request exit the client but not reaching the server than something in the middle is even "eating" requests
let me know what you find out.
As thing turned out it may be good also to set the LightstreamerLogger.connections.http category to DEBUG.
HTH