dhq deploys do not trigger Rollbar notifications

Deployments created through the API (POST /projects/<permalink>/deployments, in our case via the dhq CLI) do not trigger the Rollbar integration, while deployments started from the web UI or from a repository webhook do. We noticed it because two API-created production deployments completed successfully but never appeared in Rollbar's deploy list. Their "Delivering webhook notifications" step logs only the Slack delivery; there is no Rollbar line at all, neither a success nor a failure. Every UI-started deployment to the same server on the same day logs both the Slack delivery and "Delivered integration payload to Rollbar for production", and those revisions are present in Rollbar. We can also see that genuine delivery failures are logged: two config-file-only deployments that day report "Client error when delivering integration: the server responded with status 422" and "Failed to deliver integration payload to Rollbar for production", so the missing line indicates the integration is not being scheduled rather than failing. The project's integrations have not been modified in months, and the deployment objects returned by the API are identical between the UI-created and API-created cases apart from deployer, revisions and timestamps. Is it expected that API-created deployments skip the Rollbar integration, and if not, what would prevent delivery in this case?