Plex on LG OLED55B16 - transcoding

Server Version#: 1.32.6.7557
Player Version#: 5.69.1 (platform 6.3.3)

Plex server transcodes big chunk of my videos from NAS (Synology 220+), but LG native app Media Player directly plays everything, even HDR content (for free). CPU load are 80-100% vs 5%.

How to configure Plex server to only handle over files to TV, which decodes video files itself?
Allowed Direct Play/Stream, hardware transcoding, subtitles off etc. - little or no help.

If the native LG Media Player has a better interface, I’ll just get rid of Plex. But I want to give it a chance.

Still cannot understand why Plex needs to transcode files while TV can manage it itself.