On my machine, there is no open IPv6 port, so it cannot work. Could you please check that too?
Code:
LANG=C netstat -tunlp | grep -E '(^Proto|8006)'
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:8006 0.0.0.0:* LISTEN 5357/pveproxy