Error Pleks upstream sent too big header while reading response header from upstream plesk nginx

Debemos incluir en las directivas de Nginx dentro de nuestra suscripción de plesk

client_header_buffer_size 32k;
large_client_header_buffers 16 32k;
proxy_buffering on;
proxy_buffers 4 256k;
proxy_buffer_size 256k;
fastcgi_buffer_size 128k;
fastcgi_buffers 16 128k;

proxy_connect_timeout 1200s;
proxy_send_timeout 1200s;

fastcgi_send_timeout 1200s;
fastcgi_read_timeout 1200s;