TCP mode empty response from WAN

Hello!
I have a HAProxy instance with port 80 TCP and port 443 TCP. The 443 https works great. If I try to connect from the WAN side (pfsenwe with NAT) on port 80 I only get an empty response, but the 443 works great. If I connect internally with local dns resolving to haproxy everything works great. What could cause this?
The part of my config:

frontend http_in
    mode tcp
    option tcplog
    bind *:80
	
	acl linuxSrv 	hdr(host) -i mail.example.hu
    use_backend linux_http if linuxSrv
	
backend linux_http
    mode http
    server nginx_http 192.168.0.x:80