Auto Discover not working even though it tests fine on https://www.testexchangeconnectivity.com/

I'm on 11.3.0 HF 6 and running iApp template f5.microsoft_exchange_2010_2013_cas.v1.2.0

 

I can not get autodiscovery to work properly (it used to work before on an old iApp)

 

https://www.testexchangeconnectivity.com/ says everything is fine

 

Using an iPhone on 6.1.3 I put in my account and password. Is comes back very quickly that it is "unable to verify account information" and it populates all the fields EXCEPT domain. When I add the domain its fine.

 

Anyone ever heard of that? Thanks, Misty