After few hours i see that multicast stops propagate. Disable igmp snooping [vlan] helps.
I suppose it's some bug in XOS, no info, errors in logs. My topology is only L2 with many vlans. It happens even within one switch. My xos 188.8.131.52 v1531b4-patch1-18. Looking for some info about known bugs, limits or info with soft is best to resolve this case.
big thanks for help