I created a form with check boxes. When I uncheck the box, I am unable to recheck the box. How do I format check boxes so that a box can be rechecked after it has been unchecked?
Sounds like you used a radio-button, not a check-box.
It's check-box. Export value is On. Does that have anything to do with it? Should the export value be blank/empty?
No, it has nothing to do with the export value. Please share the file for further help.
Report the issue to the developers of these browser PDF plugins, and instruct your users to stick with Adobe Acrobat or Reader.