Android Skype for Business issue with Exchange iApp

On a pre-v12.0 system, go to System ›› Logs : Configuration : Options and enable Debug for Access Policy and SSO. On v12 and later, click Access Policy ›› Event Logs : Log Settings, select the log-settings you have assigned to your virtual, click Edit>Access System Logs, and make sure Access Policy, SSO, and ECA are checked. Then you can do a 'tail -f /var/log/apm' to see what APM is doing with those requests.