Slow HTTP Tunnel with HAProxy 2.8 and newer

Help!
1

Hello,

we use HAProxy on Ubuntu servers to distribute an HTTP tunnel to various backends.
Up to HAProxy version 2.6, this worked very well with the following configuration:

frontend https443
        mode http
        bind *:443 tfo ssl crt cert.pem alpn h2,http/1.1
        use_backend app00 if { something }
        default_backend not-found

backend not-found
        mode http
        http-request silent-drop

backend app00
        mode http
        server app00 some_ip:8443 ssl tfo

However, starting from version 2.8 and newer, the HTTP tunnel with this configuration has become extremely slow. I can only solve the problem with the following new configuration:

listen https443tcp
        mode tcp
        bind *:444 accept-proxy tfo
        server https443tcp /https443.sock send-proxy-v2

frontend https443
        mode http
        bind /https443.sock user haproxy group haproxy mode 660 accept-proxy tfo ssl crt cert.pem alpn h2,http/1.1
        use_backend app00 if { something }
        default_backend not-found

backend not-found
        mode http
        http-request silent-drop

backend app00
        mode http
        server app00 /app00.sock ssl send-proxy-v2 tfo alpn h2,http/1.1

listen app00tcp
        mode tcp
        bind /app00.sock user haproxy group haproxy mode 660 accept-proxy 
        server app00tcp some_ip:8443

I have to add incoming and outgoing tcp listeners.
What could be the cause of this?