On the 2021 Form 1099-DIV, under the Instructions for Recipient, the instructions for Box 2a should reference boxes 2b, 2c, 2d, and 2f instead of boxes 2c, 2d, 2e, and 2f. The amount shown in box 2a is not affected.
Copies of the form as posted on ibet.gov/form1099div that you may have downloaded prior to March 8, 2021, are still useable.