v2.15.1 - Impossible to get a new cert

Checklist

• Have you pulled and found the error with jc21/nginx-proxy-manager:latest docker image?
  • Yes
• Are you sure you're not using someone else's docker image?
  • Yes
• Have you searched for similar issues (both open and closed)?
  • Yes

Describe the bug
When i try to get a new cert it fails with an "internal error" message.

In letsencrypt.log :

2026-06-03 17:03:37,186:DEBUG:certbot._internal.log:Exiting abnormally:
Traceback (most recent call last):
File "/opt/certbot/bin/certbot", line 6, in
sys.exit(main())
~~~~^^
File "/opt/certbot/lib/python3.13/site-packages/certbot/main.py", line 18, in main
return internal_main.main(cli_args)
~~~~~~~~~~~~~~~~~~^^^^^^^^^^
File "/opt/certbot/lib/python3.13/site-packages/certbot/_internal/main.py", line 1886, in main
return config.func(config, plugins)
~~~~~~~~~~~^^^^^^^^^^^^^^^^^
File "/opt/certbot/lib/python3.13/site-packages/certbot/_internal/main.py", line 1598, in certonly
lineage = _get_and_save_cert(le_client, config, sans, certname, lineage)
File "/opt/certbot/lib/python3.13/site-packages/certbot/_internal/main.py", line 143, in _get_and_save_cert
lineage = le_client.obtain_and_enroll_certificate(sans, certname)
File "/opt/certbot/lib/python3.13/site-packages/certbot/_internal/client.py", line 533, in obtain_and_enroll_certificate
cert, chain, key, _ = self.obtain_certificate(sans)
~~~~~~~~~~~~~~~~~~~~~~~^^^^^^
File "/opt/certbot/lib/python3.13/site-packages/certbot/_internal/client.py", line 434, in obtain_certificate
orderr = self._get_order_and_authorizations(csr.data, self.config.allow_subset_of_names)
File "/opt/certbot/lib/python3.13/site-packages/certbot/_internal/client.py", line 512, in _get_order_and_authorizations
authzr = self.auth_handler.handle_authorizations(orderr, self.config, best_effort)
File "/opt/certbot/lib/python3.13/site-packages/certbot/_internal/auth_handler.py", line 104, in handle_authorizations
self._poll_authorizations(authzrs, max_retries, max_time_mins, best_effort)
~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/opt/certbot/lib/python3.13/site-packages/certbot/_internal/auth_handler.py", line 208, in _poll_authorizations
raise errors.AuthorizationError('Some challenges have failed.')
certbot.errors.AuthorizationError: Some challenges have failed.

Nginx Proxy Manager Version
v2.15.1

I pruned docker's image and pulled it again to be sure current was not corrupted

To Reproduce
Steps to reproduce the behavior:

1. Create a new host
2. Ask for a new cert
3. Tells an internal error occured

Operating System
Docker container under ubuntu server

Start with letsencrypt.log and the certbot traceback under /opt/certbot/lib/python3.13/site-packages, then reproduce the certificate request in the Docker container on Ubuntu. Trace the failed authorization challenge and verify that requesting a new certificate completes without the internal error.