Plex Transcode because of .srt subtitle with HDR

Server Version#: 1.43.1.10611
Player Version#: 5.94.1

I have a problem where a movie would transcode when I enable the embedded .srt subtitle on my LG OLED C5, and it would work fine as a direct stream when I play it with my LG OLED C3.

This works fine with Dolby Vision, and SDR, but it’s completely broken with HDR

I can watch direct play normally with the subtitle disabled

When I try to force direct play, I get a playback error with the subtitle enabled

Both of them use the same settings, and they are both at the same update, the only difference is the TV software update

LG OLED C5: 33.30.97 (The newest I can update)

Model Code: OLED65C56LA.AMVQLJD (I don’t know why it’s so long)

LGOLED C3: 33.31.20 (The newest I can update)

Model Code: OLED65CS3VA

Good news, in the latest firmware update from LG, this has been solved (33.31.22) released on 2026/5/14

It was slowly rolling out to everyone