I purchased an iPhone 6SPlus two weeks ago. When I created my work email account, which is Exchange 2003 (yeah, a dinosaur), I have no problems getting and sending mail and have no problems adding events to my calendar. My problem is that when I click on an event in my calendar, it doesn't open it up. It goes right to the lock screen.
I had the iPhone 5C and it did not do this.
How can I fix tapping an event to reveal the details?