While deploying this as a web interview, the last option (NA) is pre-selected, but is not saved unless another option is selected. To select NA, another option has to be selected first and then NA again. If left to the default selection, the answer is recorded as Not answered.
Changing the value of the last option to 5 instead to 0 fixed this.
I was about to post the same problem just now. Maybe I can contribute some more details:
Situation: web survey with preloading of some questions.
Some of the not preloaded questions are shown in the interview as already answered with the option which has code 0.
They are all categorical single-select questions with an answer option with code 0.
None of the categorical single-select questions that do not have an answer option of 0 gets erroneously preloaded.