[Question] ngx.execute doesn't work correctly (at least in my case)

[Zorono]

I am trying to add support for my FastCGI & ExpressJS pages using internal routes like

location ~ /@ExpressJS(/+)?(([a-zA-Z0-9\_\-]+(/+))+)? {
    internal;
    rewrite ^/@ExpressJS/(.*)$ /$1 permanent;
    root /var/www/htdocs;
    proxy_pass $scheme://127.0.0.1:$_proxy_port$request_uri;
    proxy_set_header Host $http_host;
    proxy_http_version 1.0;
    proxy_ssl_server_name off;
    # some directives for SSL and security related directives and cache
}

location ~ /@FastCGI(/+)?((([a-zA-Z0-9\_\-]+(/+))+)?([a-zA-Z0-9\-\_]+\.php))? {
    internal;
    rewrite ^/@FastCGI/(.*)$ /$1 permanent;
    root /var/www/htdocs;
    try_files $uri $request_uri =404;
    fastcgi_pass 127.0.0.1:25680;
    fastcgi_index index.php;
    fastcgi_split_path_info ^(.+\.php)(/.+)$;
    fastcgi_param DOCUMENT_ROOT $document_root;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    fastcgi_param SCRIPT_NAME $fastcgi_script_name;
    fastcgi_param SERVER_PORT $balancer_port;
    #fastcgi_param HTTP_VERSION 2.0;
    fastcgi_param PATH_INFO $fastcgi_path_info;
    fastcgi_param PATH_TRANSLATED $document_root$fastcgi_script_name;
    fastcgi_param QUERY_STRING $query_string;
    fastcgi_param REQUEST_URI $request_uri;
    fastcgi_param DOCUMENT_URI $document_uri;
    fastcgi_param SERVER_PROTOCOL $server_protocol;
    # some security related directives and cache...
}

-- some kind mechanism to handle routes dynamicaly : ExpressJS
                    ngx.exec("/@ExpressJS", ngx.var["request_uri"])
                    ngx.log(ngx.DEBUG, "#1 : " .. uri)
                    
-- some kind mechanism to handle routes dynamicaly : FastCGI
                    ngx.exec("/@FastCGI", ngx.var["request_uri"])
                    ngx.log(ngx.DEBUG, "#1 : " .. uri)

I am using internal routes to catch handle fastcgi requests after being routes through Lua based mechanism (which is almost working perfectly except for Query arguments) and I tried opening phpMyAdmin, but it is not fully working because of some kind of issues with the Query Arguments which is not respected and i tried many times to solve it like

ngx.exec("/@FastCGI" .. ngx.var["uri"], ngx.var["args"])

but it results in *1 rewrite or internal redirection cycle while internally redirecting to "/@FastCGI/phpmyadmin/index.php"