Queue time in stats page despite not reaching maxconn

In the HAProxy stats page, it displays on some of my backends a Queue Time of ~2s. I don’t understand why some requests are being queued despite maxconn being set to 60000 (it never reached that value).
Here is my conf:

global
  daemon
  chroot       /var/lib/haproxy
  user         haproxy
  group        haproxy
  maxconn      60000
  stats socket /var/lib/haproxy/stats

defaults
  mode                    http
  log                        global
  option                  dontlognull
  option forwardfor       except 127.0.0.0/8
  option                  redispatch
  retries                 3
  timeout http-request    5s
  timeout connect         2s
  timeout client          5s
  timeout server          5s
  timeout http-keep-alive 1800s
  timeout check           5s

frontend main
  bind        127.0.0.1:83
  use_backend %[req.hdr(host),lower,word(1,.)]
  stats uri   /api/v1/haproxy-stats

resolvers resolv-conf
  parse-resolv-conf
  accepted_payload_size 8192
  timeout resolve       20s

backend someBackend
  http-reuse      always
  http-request    set-header Host someBackend.net
  balance         roundrobin
  server-template aka_ 9 someBackend.net:80 check resolvers resolv-conf resolve-prefer ipv4

What am I missing ? Also, strangely, in the stats page, the session limit is set to 1 on all of my backends:

1 post - 1 participant

Read full topic