Hi @alex1962 - You should open a bug report with the maintainers of pfsense. I'm not familiar with this project and unfortunately can't find the right place to file a bug report myself on your behalf.
When you open a bug report please let the authors know that updating the hardcoded value to the new agreement URL is not the best fix - it will only break again in the future when we change the URL. The ACME protocol supports learning the current URL at runtime so that it is never out of date and the pfsense ACME client should be updated to learn the URL that way to avoid hardcoding.
It worked until a week ago because we changed the subscriber agreement on Nov 15th.