Haproxy 1.8 cache

Hi all,

I have some problem with the cache functions. cached is filled I checked it over socat but there is no reference count and the cache is not used. I use haproxy 1.8.3

0x7fade115f42c hash:794218 size:760 (1 blocks), refcount:0, expire:3183
0x7fade10cc90c hash:996187 size:2367 (3 blocks), refcount:0, expire:3182
0x7fade10d512c hash:20539863 size:1702 (2 blocks), refcount:0, expire:3182

The response header from the backend-server contain the following headers.
Cache-Control:max-age=563395, must-revalidate
Content-Length:823
Content-Type:image/png
Etag:“20170530182128”

Is any of this headers block haproxy to deliver from cache?

the backend looks like that

backend events_BE_static
mode http
timeout server 300s
timeout connect 2s
timeout http-keep-alive 1s
option http-server-close

    timeout check 2s

    balance roundrobin

    http-request cache-use events
    http-response cache-store events

    no option redispatch
    server s1-104-8080 xxx:8080 check weight 100 maxconn 75
    server s2-104-8081 xxx:8081 check weight 100 maxconn 75
    server s3-102-8081 xxx:8081 check maxconn 75 backup inter 1s fall 3

cache events
total-max-size 200
max-age 3600

Thanks for your help.

cheers hans0r