Issue with SSI in Docker + Nginx + Swoole with Symfony

[MeshkovaNatalia]

I'm trying to use Server Side Includes (SSI) in my Symfony project, which is running in a Docker environment with Nginx as a proxy server and Swoole as a PHP extension. The problem is that SSI render requests aren't happening when using Swoole, although everything works fine with FastCGI Process Manager (FPM).

Problem Description: I have SSI enabled in my Symfony configuration file:

framework:
  ssi: { enabled: true }

In my Twig template, I'm using render_ssi to call a Symfony controller:

{{ render_ssi(controller('my.app.controller::appAction')) }}

When requesting a page that contains this SSI, no render requests are happening in Swoole.

Nginx Configuration: Here's my Nginx configuration file:

proxy_cache_path /var/lib/nginx/cache/assets levels=1:2 keys_zone=assets:50m max_size=512m;

server {
    listen 80;
    server_name _;

    ...

    location ~ ^/index\.php(/|$) {
        ...

        ssi on;
        ssi_value_length 1024;

        proxy_pass http://127.0.0.1:8000$request_uri;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header Surrogate-Capability "device=\"SSI/1.0\"";
        proxy_set_header X_SUPPORT_PROXY_MEDIA "1";

        proxy_cache assets;
        proxy_no_cache $disable_cache;
        proxy_cache_bypass $disable_cache;
        proxy_cache_valid 200 7d;
        proxy_cache_key "$request_uri";
        proxy_cache_use_stale error timeout invalid_header updating http_500 http_502 http_503 http_504;

        ...
    }
}

What I've Tried:

Verified that SSI works with FPM.
Tried changing various Nginx configuration parameters, but it didn't solve the issue.
Expected Outcome: I expect render requests for SSI to work successfully through Swoole.

Question: Are there any additional configuration settings needed to support SSI with Swoole in my Docker + Nginx + Swoole environment with Symfony?