The iOS device logs will show: Authentication: Authentication Interrupted.
This has been encountered when the SSL certificate is a wildcard certificate for the entire domain such as *.contoso.com. The root domain such as https://contoso.com works correctly. Subdomains such as https://crm.contoso.com do not work as expected. This may be due to compatibility with iOS devices and certificates that list wildcard Subject Alternative Names. It is recommended to test with certificates whose root level includes the CRM subdomain such as *.crm.domain.com.
Article ID: 3069747 - Last Review: 02 Jun 2015 - Revision: 1