Intermittent 404 model_not_found on muse-spark-1.3 — likely a rollout-side issue
Developers report intermittent 404 model_not_found errors calling muse-spark-1.3 on api.meta.ai, with identical calls succeeding minutes apart and /v1/models briefly returning an empty list. The pattern across two API keys points to a routing or capacity issue on Meta's side during the Spark rollout rather than client misconfiguration.