No @Dougers1 you should show the question/selection that is in your form so we can see the potential inputs.
You could also show the selections that were made when the form errored.
If I had to guess, it is probably due to text not matching. If your form has a selection "NHS Computer Login" but your switch case is "NHS computer login" then it will not match because the two letters C and L do not match c and l due to capitalization.
Similarly if there were additional spaces or anything in the field.
This will also not work if there are multi-selection options and the person can select more than one value for the same question.