Struggling with Nginx reverse proxy configurations causing unexpected latency and connection resets

We're currently experiencing significant performance degradation and intermittent connectivity issues with our new Nginx reverse proxy implementation. Specifically, I'm observing high latency and frequent connection resets that don't appear when accessing the backend directly, which points to the proxy layer. I'm seeking advanced troubleshooting steps or common pitfalls for complex reverse proxy setups beyond basic keepalives or timeout adjustments. Help a brother out please...