Samsung TV transcoding EAC5.1 even though it can direct play it

I’m using the Plex app on my QN55Q80CAFXZC TV connected to my Q660 soundbar with rear surround speakers via eARC. When I play something with EAC5.1 audio it transcodes the audio to AAC5.1. However, if I turn on Force Direct Play in Plex then it direct streams the EAC5.1 audio and plays it fine. I can’t leave that settinb on though because then it won’t transcode DTS which the TV doesn’t support. Why is it transcoding a codec it can clearly play and how do I get it not to? Thanks!