@miconda: in this case we should also disable NPN negotiation: https://curl.se/libcurl/c/CURLOPT_SSL_ENABLE_NPN.html, or even disabling HTTP/2 completely setting CURLOPT_HTTP_VERSION (current curl default value is CURLOPT_HTTP_VERSION_2TLS). I didn't want to be so extreme :) @bjokax, thanks for testing it.