What about wired devices? So your computer (wired) and TV wired?
I would fire up say wireshark while in this setup. Do you see the SSDP stuff from TV? then check while wireless and do you see this traffic from wireless devices, but not wired?
I don't use dlna, just don't see the point to be honest
My media player just pulls my media via smb on my nas, plays on my TV.
And my mediaplayer (popcorn hour) and both dvrs are on dumb switch in the living room.. So it just dawned on me that now that router is vm on esxi host I can run this connection into my smart switch... And then moved my envi current bridge that has a freaking multicast mac -- stupid company!! And can not locally fix it. And since my router is now VM I don't need the span ports of my smart switch any longer so could put the envi and the n40l lan connected to dumb switch and enable igmp snooping (blocking multicast) on my smart switch. Now way less multicast noise when sniffing on my workstation