Quick checklist:
- Save raw ChatGPT output to logs/Google Sheet before sending.
- Ensure Zapier sends HTML (convert Markdown→HTML, don’t escape entities); put content into WP REST “content” field.
- Inspect Zapier task history and WP response headers for X-RateLimit-Remaining / Retry-After.
- Handle 429s with exponential backoff + jitter: 3 retries at 2s, 4s, 8s (+0–500ms).
- Throttle or batch posts (aim ≤1 req/sec).

If you want an alternative with built-in retry/throttle controls, compare Zapier vs Make: Compare Zapier and Make