You asked me to confirm my community - why?

Because the mapping improves over time, and you get asked to confirm rather than silently corrected.

Your community was worked out from your surname and native district. As the mapping grows, your options can change — a community that was not offered before may appear, or the list may narrow. When that happens, you will see the new options beside what you already have, with what changed named out loud, and you pick. Keeping what you have is always a valid answer.