What's currently configured in this folder on your broker?  C:\Program Files\VMware\VMware View\Server\sslgateway\conf

I ask because we had a hiccup with our f5 config early on and needed to add the following lines to the locked.properties file:

serverProtocol=http

checkOrigin=false

The serverPRotocol=http was in our config from the start to get the f5 setup to work.  We added checkOrigin=false after the Horizon 7 upgrade for this: VMware Knowledge Base