Addressing Upstream Header Overflows in Elementor Storefronts

Nginx FastCGI Buffer Tuning for Digital Product Downloads I recently migrated a digital goods store to the Digitax - Elementor Digital Store WooCommerce WordPress Theme. The environment was a standard LEMP stack running on Debian. During post-deployment testing of the digital download fulfillment path, the system intermittently returned 502 Bad Gateway errors. This occurred specifically when the application attempted to redirect the user to the secure download link generated via the WooCommerce API. The error was not persistent, which ruled out a static configuration fault or a dead PHP-FPM socket. I checked the Nginx error_log immediately. The logs contained a specific entry: "upstream sent too big header while reading response header from upstream". This indicated that the response headers being passed from PHP-FPM to Nginx exceeded the default buffer limits. Digital download platforms, particularly those utilizing Free Download WooCommerce Theme logic for lead magnets or freebies, o