The aura component shows a list of text messages. Vertical scrolling does not work in iOS on the Salesforce 1 app. Works fine in Android. I looked at a few other questions like Scroll issue in Salesforce1 | Lightning ui:scrollerWrapper issue but the solutions are not working for me.
The issue is that it scrolls the salesforce 1 mobile app and not the component ui:scrollerWrapper. The component is embedded in another aura component. However in android it is able to scroll the ui:scrollerWrapper.