IGMP issues

[dotOne]

Since this (https://forum.pfsense.org/index.php?topic=93293.0) thread is already quite old I'm starting a new one.

Currently my ISP is moving from a bridged IPtv to a routed network to provide extra services.
Internet connection is provided via a vlan (vid 6) with PPPoE.
IPtv is provided via another vlan (vid 4) with DHCP.

The provider uplink is connected to a MRV OS910 CPE that strips the vlan 4 tag from the IPtv traffic and sends it untagged to the TV network.
Internet traffic is sent tagged to the firewall. The firewall has a vlan 6 configured running PPPoE.
Hence it was quite easy to create a routed configuration. I just had to create vlan 4 on the firewall, request an IP with DHCP and reconfigure the CPE to send vlan 4 to the firewall as well.

The IPtv network is running multicast for the actual TV and a unicast network (213.75.0.0/16) for provisioning the TV receivers and provide sender information.
I configured NAT for the unicast network on the IPtv interface.
This all works like a charm.

On the multicast side the IGMP is giving me some headaches.
I configured the IGMPproxy the LAN interface as downstream and the IPtv vlan interface as upstream

So far so good, provisioning of the receivers is running fine.
The problem starts when watching television, it looks like there is something wrong with the multicast forwarding. every time watching TV stops after 2 seconds.

According to this post https://forum.pfsense.org/index.php?topic=93293.0 the IGMP deamon is a bit buggy so I installed the latest version:

pkg
pkg update
pkg install igmpproxy

but now, as mentioned a bit further on in this thread, https://forum.pfsense.org/index.php?topic=93293.msg543938#msg543938 ,the vlan interface is not recognized anymore.
It seems however that this version of the igmpproxy is really looking at the physical interface level.
I put a dummy IP adres on the physical interface and used that as the upstream interface.

The IGMP and multicast flows are still recognized and processed.
Sadly enough moving to this version of the igmpproxy did not help, flows stop after 2 seconds.

Anyone have a bright idea?

Update:
I moved back to the original igmpproxy.
Sometimes I can watch TV for 30 seconds and then it stops.