The Plex Media Server is not sending the "Hey, I'm a 3D signal, need to switch" to the 3D capable display.
Of all the devices I have that can stream 3D MKV's to my display the ONLY one that is not working is the signal coming from the Plex Server. Image is side by side but not processed. The TV doesn't know its a 3D signal.
This should happen automatically with the 3D information in the signal coming from the Plex Media Server.
My Meder8er does so just fine. The information that tells the TV to switch to 3D mode is buried in the HDMI signal.
The Plex Media Server is doing something with that information. Not sending it? Sending it but its corrupt? Something is not being included in the signal that IS in the mkv, is being sent by other media playback devices.
I've noticed others posting same kind of issue. Some say its not up to the Plex Server to makes sure the TV sets to 3D.
That is true but not the WHOLE story.
The signal coming into the display via HDMI has to include the 3D trigger. And for THAT the Plex Media Server is in play.
Given all other media devices that stream the same MKV file, and yes it is named correctly as the TV shows the side by side images, work this is something about what the Plex Media Server software is not doing correctly.