Can only cast to Chromecast from clients connected to same access point in network

[link00seven]

Hi everyone,

I currently have my Chromecast connected to my RT-N66U which is running as a wireless repeater. My primary router is an RT-AC68U - both devices are running Asuswrt-Merlin.

Unfortunately, in regards to the Chromecast device - any clients (like my desktop PC), that are connected to the primary router (AC68U) are not able to cast to the Chromecast. Only clients connected to repeater (N66U) are able to cast correctly.

Surprisingly enough, when my iPhone is connected to the N66U, and I open the PLEX app (which connects to my PLEX server on the AC68U) and cast, it works - so my devices appear to be able to talk to each other it's simply the casting that doesn't work in this way.

I've tried the following:

• N66U is not assigning IPs at all (no DHCP)
• All devices are on the same subnet (everything is within the 192.168.1.x range)
• AP Isolation is disabled (on the AC68U - this setting is hidden from the N66U in repeater mode)
• IGMP Snooping (multicast forwarding) is enabled (on the AC68U - this setting is hidden from the N66U in repeater mode)
• IGMP Proxy (multicast routing) is enabled (on the AC68U - this setting is hidden from the N66U in repeater mode)

Does anyone have other ideas that I could try to get this working?

Thanks for your help!