In the Plex forums I think @Elan said that you may need to upgrade the Plex server manually as the NAS hardware updates tend to be slow. Only the latest Plex server can communicate with the ATV4.
At the moment both the Plex server server + ATV4 client is free. You need to buy the ATV4 though.
I'd be more attentive to the network bandwidth. Is it a plugged ethernet cable between the two devices, or wifi?
At the moment both the Plex server server + ATV4 client is free. You need to buy the ATV4 though.
I'd be more attentive to the network bandwidth. Is it a plugged ethernet cable between the two devices, or wifi?