Bot Builder API 500 on Intent Update During High-Volume Sync

Looking for advice on a recurring 500 Internal Server Error when updating intent entities via the Bot Builder API (/api/v2/bots/{botId}/languages/{languageCode}/intents). The integration handles bulk intent synchronization for a client in eu-west-1, hitting the endpoint every 5 minutes with ~500 intents per batch. Rate limiting headers show plenty of quota remaining, yet the backend consistently fails on complex intent updates with nested entities. Config snippet below:

sync_config:
 batch_size: 500
 interval_minutes: 5
 endpoint: /api/v2/bots/{botId}/languages/{languageCode}/intents
 retry_logic: exponential_backoff

Anyone seen this specific 500 pattern during high-volume intent pushes? Need to know if this is a known platform limitation or a payload structure issue.