Big IP Reverse Proxy Does not Seem to be passing traffic onto my Skype for Business Front End Servers

Hey all. I posted a question a little while ago but i never really got an answer because I think I overworded it. Long story short, I have all of my Skype for Business internal and external services running (AV, IM, and presence). I set up a DMZ Big IP set to forward reverse proxy traffic to my FE servers using the iAPP.

When I connect to the public IP/URL NAT'd to the device, I get a certificate warning (have not set up SSL yet) but then I cannot connect. I can see the three FE servers lit up as green from the Big IP so I know they're connected, but when I run wireshark I don't see any extra traffic flowing from the Big IP to my FE servers when I attempt a sign in so I'm not sure that the traffic is even getting through the Big IP and I'm not sure why. Does anyone have any thoughts on this? I have 443, 80, 4443, and 8080 allowed from my Big IP to my FE servers so I do not believe it is my firewall but I could be wrong.

Any help would be appreciated. Thanks all!