Forms populating 'other' as an answer

Evening All,

My research survey is currently active on Microsoft Forms. One of my questions has populated 'other' as an answer; however, 'other' is not an answer on this particular question. When clicking on more details the correct answer is shown, as in excel when I open it. Additionally this question's responses is the only one shown in graph format, the rest are pie. Respondents are not able to edit the survey or add 'other' as an answer, so I'm not sure how this has occurred.