Unable to add tags to closed tickets

Hello,

It seems not possible to add tags to closed tickets, even though the option to edit tickets is enabled in admin center and I can already edit closed tickets in agent workspace and API.

Here is what the logs show:

{
  "id": "01K97BEBDJJWTSEHEZX0QJHXXM",
  "timestamp": "2025-11-04T11:53:39Z",
  "product": "Action flows",
  "service": "flowstate",
  "level": "error",
  "message": "Zendesk request failed with 422 response",
  "fields": {
    "end_time": null,
    "execution_id": "01K97BEB2R914HPZTDXPMXBFMH",
    "start_time": "2025-11-04 11:53:38.648542 +0000 UTC",
    "status": "FAILED",
    "step_executions": [
      {
        "frame": "",
        "start_time": "2025-11-04 11:53:38.694831 +0000 UTC",
        "step_execution_state": "DONE",
        "step_id": "01K97BD34PYZX6PJE0EQCGPPGS",
        "step_name": "Custom code",
        "step_type": "custom_code"
      },
      {
        "error": {
          "category": "EXTERNAL",
          "http_status_code": 422,
          "message": "failed to add ticket tags 422: {\"error\":{\"title\":\"BadRequest\",\"message\":\"One of the updates to a closed ticket was rejected\"}}"
        },
        "frame": "",
        "start_time": "2025-11-04 11:53:38.867072 +0000 UTC",
        "step_execution_state": "FAILED",
        "step_id": "01K97BD34PYZX6PJE0F2KT180H",
        "step_name": "Add tags to ticket",
        "step_type": "tickets_addTicketTags"
      }
    ],
    "trigger": "My trigger",
    "workflow_id": "01K8TDTC97FAEBESF2Q9SQAVXM",
    "workflow_name": "My workflow",
    "workflow_version_id": "01K97BD34H3BPJXCS7DYD7Z9NC"
  }
}

Update: as a workaround I used custom actions instead which overcomes this error. Please look into the limitations of native ticket actions (both update ticket and add tags) with respect to closed tickets.