There is a bug in the Nintex Form Build number 220.127.116.11:
If you create a rule in order to disable a checkbox, the value of the checkbox will be reset to False in the FormData even though it was True in the Form.
bug reporting checkboxes#
Hey there... I had this exact issue the other day.. I just finished installing the latest version that went out yesterday and it has fixed it for me.. This was a pretty big maintenance release.. Check the change log here..