How to reproduce:
1. Open the attached project
2. Open MainScene scene
3. Expand Parent and select Cube
4. Go to Add Tag
5. Create new tag called like existing one PDFace
6. Then delete it
7. Select Cube again and notice that its tag is Undefined
8. Change its tag to Untagged
9. Play the scene
10. Try typing to InputField
11. Notice when one starts typing carrot jumps to the middle and text appears only when one clicks on InputField with mouse again

Workaround:One should use the required tag

Not reproducible: 5.2.4p1
User error related to deleted tag.