Error when syncing repository with only errata

Hi
Problem:
I’m trying to sync a repository containing only Errata information (no RPM) (something provided by @vulnersCom ) documentation is here : Install relevant security updates for CentOS with Errata plugin from Vulners – Vulners Blog
However, when trying to sync It I receive a : “Could not parse repository metadata”

The URL for the repostory is :
https://< redacted api key >@vulners.com/errata/centos/7/
so I’m wondering if the “@” doesn’t cause trouble.

Running a Curl : curl https://@vulners.com/errata/centos/7/repodata/repomd.xml
Gives me a correct XML file.
Configuring the repostory in a .repo file for yum.conf works properly and I’m able to see the errata
Expected outcome:
No issues

Foreman and Proxy versions:
katello 3.18.2.1

Distribution and version:
CentOS 7
Other relevant data:
The full error in dynflow is :

---
pulp_tasks:
- exception: 
  task_type: pulp.server.managers.repo.sync.sync
  _href: "/pulp/api/v2/tasks/d9914806-6e36-4fe2-93f6-51551b5d0084/"
  task_id: d9914806-6e36-4fe2-93f6-51551b5d0084
  tags:
  - pulp:repository:0f63907b-a33f-46bc-aa65-db0f4671ba47
  - pulp:action:sync
  finish_time: '2021-07-02T15:54:46Z'
  _ns: task_status
  start_time: '2021-07-02T15:54:41Z'
  traceback: |
    Traceback (most recent call last):
      File "/usr/lib/python2.7/site-packages/celery/app/trace.py", line 367, in trace_task
        R = retval = fun(*args, **kwargs)
      File "/usr/lib/python2.7/site-packages/pulp/server/async/tasks.py", line 688, in __call__
        return super(Task, self).__call__(*args, **kwargs)
      File "/usr/lib/python2.7/site-packages/pulp/server/async/tasks.py", line 110, in __call__
        return super(PulpTask, self).__call__(*args, **kwargs)
      File "/usr/lib/python2.7/site-packages/celery/app/trace.py", line 622, in __protected_call__
        return self.run(*args, **kwargs)
      File "/usr/lib/python2.7/site-packages/pulp/server/controllers/repository.py", line 802, in sync
        sync_report = sync_repo(transfer_repo, conduit, call_config)
      File "/usr/lib/python2.7/site-packages/pulp/server/async/tasks.py", line 905, in wrap_f
        return f(*args, **kwargs)
      File "/usr/lib/python2.7/site-packages/pulp_rpm/plugins/importers/yum/importer.py", line 84, in sync_repo
        report = self._current_sync.run()
      File "/usr/lib/python2.7/site-packages/pulp_rpm/plugins/importers/yum/sync.py", line 285, in run
        metadata_files = self.check_metadata(url)
      File "/usr/lib/python2.7/site-packages/pulp_rpm/plugins/importers/yum/sync.py", line 443, in check_metadata
        raise PulpCodedException(error_code=error_codes.RPM1006)
    PulpCodedException: Could not parse repository metadata
  spawned_tasks: []
  progress_report:
    yum_importer:
      content:
        items_total: 0
        state: NOT_STARTED
        error_details: []
        details:
          rpm_total: 0
          rpm_done: 0
          drpm_total: 0
          drpm_done: 0
        size_total: 0
        size_left: 0
        items_left: 0
      comps:
        state: NOT_STARTED
      purge_duplicates:
        state: NOT_STARTED
      distribution:
        items_total: 0
        state: NOT_STARTED
        error_details: []
        items_left: 0
      modules:
        state: NOT_STARTED
      errata:
        state: NOT_STARTED
      metadata:
        state: FAILED
        error: Could not parse repository metadata
  queue: reserved_resource_worker-2@master-repo.dq2
  state: error
  worker_name: reserved_resource_worker-2@master-repo
  result: 
  error:
    code: RPM1006
    data: {}
    description: Could not parse repository metadata
    sub_errors: []
  _id:
    "$oid": 60df36c1ea87eefc30e62509
  id: 60df36c1ea87eefc30e62509
contents_changed: true
poll_attempts:
  total: 8
  failed: 1

thank you