Cursor disappearing in web-view input field after modal (iOS)

I have a web view in iOS where users can click into a HTML input and bring up the keyboard to type into the field. While still typing with the keyboard up, a user can click a native navigation bar button where it displays a dialog and presses cancel to dismiss the dialog. After dismissing the dialog, the user is brought back to the webview with the keyboard to continue typing. The text still shows up in the field after typing but the blue iOS cursor is completly gone. Any ideas on how to make sure the blue cursor returns?