Creating simple nma->get("https://wipikedia.org") request fails on latest iOS with Qt 5.9.0 RC with The root CA certificate is not trusted for this purpose message.
I do know know if Alpha/Beta versions failed too, because there was other issues with iOS package (missing Webview etc) so I did not test earlier.
There are no problems if I build with Qt 5.7.1.
No problems on Debian, Android and macOS with any Qt version.
Attached simple test case.