We had a customer swapping radio button controls for checkboxes and updating the field rules.

Well the system does some intelligence in the background. It checks if the value you had for the radio field exists in the new checkbox field and sets it for you (in the example below "choice 3".

So after switching only the field it looks like I am done configuring and everything looks good. After clicking save it still looks good, only after you leave and return later after testing do you see that all the values have been wiped out.