IPTV / UDP multicast problem

[shdf]

i just found this about what could be the reason :

Support MA5671A SFP GPON

It apparently this stick doesn't forward IGMP, my IPTV doesn't work with this stick but works with another "more dumb" lantiq-based stick (Sercomm FGS202) which doesn't use Openwrt

followed by this message :

Support MA5671A SFP GPON

no, it's my stock image with the OCMI modded... I don't really want to flash random images because they might hardware damage the thing by pulling the wrong I/O pin the openwrt just doesn't forward IGMP traffic, normally they have igmpproxy package for that but it require a clear LAN/WAN interface meanwhile the GPON stick doesn't really expose the L2 WAN interface to the openwrt OS so I have no idea how to make it work