If your my.avast.com shows the license for avast cleanup, can you not assign that license to your current avast installation ?

Sorry I can’t give any more practical help as I don’t use the avast cleanup function.

Check out these search returns from the FAQ section on cleanup, https://www.avast.com/faq.php?q=avast%20cleanup or the specific Cleanup FAQ https://www.avast.com/faq.php?article=AVKB211#artTitle article.