Multicast over GRE Tunnel

[awhiting]

I am trying to replace some very old Cisco gear that transmits multicast for our phone Paging.
I have a GRE tunnel setup between two vyos routers at the two sites I am testing and can ping across. I am having trouble getting the multicast from the Eth0 on R1 router down the gre tunnel.

Router 1 Where the source is

interfaces {
    dummy dum0 {
        address 10.30.200.2/32
    }
    ethernet eth0 {
        address 192.168.200.34/22
        hw-id 00:50:56:9a:8e:f4
        offload {
            gro
            gso
            sg
            tso
        }
    }
    loopback lo {
    }
    tunnel tun1 {
        address 10.11.182.2/30
        enable-multicast
        encapsulation gre
        remote 192.168.182.3
        source-address 192.168.200.34
    }
}
protocols {
    pim {
        interface dum0 {
        }
        interface eth0 {
        }
        interface tun1 {
        }
        rp {
            address 10.30.200.2 {
                group 224.0.0.0/4
            }
        }
    }
    static {
        multicast { 
            interface-route 240.0.0.0/4 {
                next-hop-interface tun1 {
                }
            }
        }
        route 0.0.0.0/0 {
            next-hop 192.168.200.5 {
            }
        }
    }
}

Router 2 were the phones are

interfaces {
     ethernet eth0 {
         address 192.168.182.3/24
         hw-id 00:50:56:9a:b9:42
         offload {
             gro
             gso
             sg
             tso
         }
     }
     loopback lo {
     }
     tunnel tun1 {
         address 10.11.182.1/30
         enable-multicast
         encapsulation gre
         remote 192.168.200.34
         source-address 192.168.182.3
     }
 }
 protocols {
     pim {
         interface eth0 {
         }
         interface tun1 {
         }
         rp {
             address 10.30.200.2 {
                 group 224.0.0.0/4
             }
         }
     }
     static {
         route 0.0.0.0/0 {
             next-hop 192.168.182.1 {
             }
         }
         route 10.30.200.2/32 {
             interface tun1 {
             }
         }
     }
 }