Before iOS 8, we used below code in conjunction with supportedInterfaceOrientations and shouldAutoRotate delegate methods to force app orie
[iOS9+] If anyone dragged all the way down here as none of above solutions worked, and if you present the view you want to change orientation by segue, you might wanna check this.
Check your segue's presentation type. Mine was 'over current context'. When I changed it to Fullscreen, it worked.
Thanks to @GabLeRoux, I found this solution.