Tick-boxes do not print after saving PDF when printing "Form Fields Only"

Hello,

I have created a PDF Form that I am using to print onto already existing hard-copies of forms. I am able to fill in the form & print only form data by using "Form fields only" option in the printer settings. This works flawlessly until I save the document and re-open it. After saving and re-opening all of the forms except the tick-boxes print. I can re-tick all the boxes and print the form again, however this is very time consuming and introduces potential for errors. Thanks in advance for any help.