Can't cast to different VLAN even with smcroute and avahi

I am trying to cast to my LG TV from my main VLAN, br-lan. The TV is on another VLAN, br-lan100.

I have smcroute installed and since then the netflix app can see the TV, but not cast to it. The youtube app can't see the TV at all.

avahi-browser is installed and configured for the two VLANs and both VLANs can talk freely to each other since they are in the same firewall zone and forwarding is enabled.

I noticed that when the phone and TV are on the same VLAN that the mDNS-testing app I am using on the phone shows two service types for the TV:

  • airplay.tcp (port 7000)
  • display.tcp (port 7250)

But when the TV is on br-lan100 while the phone is on br-lan only one shows up:

  • airplay.tcp (port 7000)

According to the app _display_.tcp advertises a "dev_name" of "MiracastR2Sink" and Type "p-sink".

Apparently I don't know what to google for because my searches haven't brought up any hints on how to set this up.