Remove the field from the form then re-add it to the form, using the following steps:
  1. From the top of an Administrator page, click Fundraising > Donation Management. 
  2. On the Campaign List page, click Manage from the Actions column of the appropriate campaign. 
  3. On the Donation Form List page, click Edit from the Actions column of the appropriate donation form. 
  4. At left, click 3, Design Donor Screens 
  5. At center, click Edit under Donation Form. 
  6. You will now see all the fields that are on your form in the grey box in the right. Select the element that is not updating and hit Remove. 
  7. Click Save at the bottom of the page. 
  8. Find the target field in the box at left. Click Edit. Click Save at the bottom of the page. 
  9. Return the target field to the form by selecting it at left, clicking Add and then Save Order and Edit Selected. 
  10. Click Save at the bottom of the page.