Adobe PDF Forms - Radio Button/Check boxes suddenly sending value of "Off"

We developed an Adobe PDF forms survey using "Prepare Forms".    Users uploaded completed surveys into our web application where some Java application code reads and processes those surveys.   Recently we noticed that for Radio Buttons and Checkboxes when a user doesn't make a selection, values of "Off" are coming in.  Previously this didn't happen.   Looks like the issue started happening sometime in mid-July.   We even were able to take a survey that did not have this problem and simply re-save the survey and were able to introduce the problem just by re-saving it.   Even worse, we have seen where the PDF file got corrupted and returned a value like "0" or "5" for a radio button selection instead of the option defined in the PDF form field properties.   For example, we had a Yes/No pair of radio buttons.  If  I go into Properties-->Options and look at "Radio Button Choice" for the "Yes" radio button, I see it shows "Yes".  However, when the survey was read in, it had a value of 0.   I was able to fix it simply by change "Radio Button Choice" property to a value other than "Yes", closing the properties window, re-opening and changing the value back to "Yes".   I then had to re-select the "Yes" option and save the PDF file.  Now when I upload it, it has the correct value again.   But then other unselected check boxes and some radio buttons are coming in with a value of "Off".   This seems to be a very new bug, that hopefully Adobe can fix.