Hello,
Unfortunately, votes are not able to be changed as they are irrevocable. Our voting system is set up to mirror the written resolution procedure for a company (as 90% of our votes are on a written resolution). Per the Companies Act, votes on a written resolution are irrevocable and so this element is mirrored into our vote system. We apologise if this is unclear, and we will ensure we make this clearer for any vote in the future.