When editing this field on the donation form, both the true and the false options need to be checked for the field to work correctly. If you've checked Display Style > Single Checkbox, it will still only display a single checkbox.

If you want the constituent's choice to show up on the Transaction Summary (for the donor) and/or on the constituent Interaction (in Constituent 360) then you would want labels for both options, or at least the positive option. When the constituent checks the box, the label chosen for True will show up next to the check-box, as well as on their Transaction Summary and on the Interaction. If they do not check the box, the label chosen for False will show up in their Transaction Summary and on the Interaction. 

If both options are selected, regardless of labels, a Transaction Details Report captures True for checked and False for not checked.