To reproduce:
1. Open project
2. Add Japanese Kana keyboard on iOS 11 device
3. Build and run on a device
4. In text field type text from the video in edit
5. Click somewhere around text field to close the keyboard(Not by pressing 'Done' key)
6. Minimize app by pressing Home button
7. Double-click home button, reopen the app
8. Press on a text field
9. Notice that there are some characters became invisible in keyboard's text field

Reproduced: 2017.2.1p2, 2018.2.3f1, 2017.3.2f1, 2017.4.6f1, 2018.1.6f1, 2018.2.0b9, 2018.3.0a3
Not reproducible: 2017.1.3p4, 2017.2.1p1