As soon as I enable FPC in Magento 2.4.2, I am getting a upstream sent too big header while reading response header from upstream error when I try searching. It does not happen for all search terms, but for most.
My shop is running on nginx so I tried adding this to the nginx.conf:
fastcgi_buffers 16 16k; fastcgi_buffer_size 32k; proxy_buffer_size 128k; proxy_buffers 4 256k; proxy_busy_buffers_size 256k;
Did not help a bit. Any ideas how to solve this?