Serviio

First off, Samsung does a lousy job with their DLNA players. I have three Samsung TVs, and I don't use the TV interface with any of them. Using a Roku, Fire TV or Nvidia Shield provides a vastly improved experience, especially if you want lossless audio, in which case you want the Shield. I downloaded the M8500 manual, so see page 29 of the owners manual for instructions on how to enable viewing media stored on a computer (they never use the term DLNA, but I'm sure that's what they are referring to). It says "Press the (Home) button. Select (Source), and then User's PC. The folders and files in your PC are listed."

Now honestly, that sounds more like they are looking at connecting to a network share, not DLNA. And the owners manual makes no mention of DLNA support at all, so it's possible you simply can't stream via DLNA. If you select Source and Serviio doesn't appear, I think you're dead in the water.

However, your player does have a web browser, so it might be possible to use it to connect to the MediaBrowser and use it that way. It also supports a number of apps, so you might search the available apps for something like VLC or another streaming player.

I'm afraid that's a Samsung issue, and nothing can be done from the Serviio side. If Serviio is working correctly on other devices, then the problem is with the TV. And as I said, Samsung just doesn't make much of an effort with their DLNA client.

I'd have to review that profile, but chances are it's trying to transcode 4K material when it shouldn't have to, so your Serviio computer is being overworked. Transcoding H.265 takes a lot of power. Just as a test, try using the Roku 4K media Player with MPEG2 profile and see how it does with your 4K material. It doesn't transcode the video at all, only the lossless audio tracks, which I can pretty much promise your player won't passthrough to your AVR.