sorry me ugly english 
if you ipt have several subnets, then igmp-proxy you must configure by this example:
#if you use firewall
/ip firewall chain=input protocol=igmp interface=WAN action=accept disabled=no
#UDP auto passed by established and related rules
#if you use client firewalling
/ip firewall chain=input protocol=igmp action=accept disabled=no
/ip firewall chain=forward protocol=igmp action=accept disabled=no
/ip firewall chain=output protocol=igmp action=accept disabled=no
#sometime must required, but not recommended
/ip firewall chain=input protocol=UDP interface=WAN action=accept disabled=no
/routing igmp-proxy
set query-interval=2m5s query-response-interval=10s quick-leave=yes
add alternative-subnets=224.0.0.0/4,your_WAN_subnet,your_ipTV_server_subnet disabled=no interface=WAN upstream=yes
add disabled=no interface=all upstream=no