In other text fields, clicking on an empty box brings the cursor.
The text fields in the layout algorithms cannot show the problem, because they are all populated with something ( not empty ).
In data entry boxes that show the blinking cursor, I noticed that, when the box is empty, the width of the cursor is narrower. I suggest you verify the alignment of the text with the box, because the cursor may be hiding left of the left box border. Other possibility, check that the width of the blinking cursor is sufficient to be displayed.