[Playback] Can not start a playback when PGSSUB is selected behind a reverse proxy (nginx)

[tykateetee]

Moonfin version

v2.4.0

Platform

Tizen (Samsung)

Platform version

Tizen 6.0

TV model

UN58TU7000FXZC

Jellyfin server version

10.11.9

Content type

Movie

Media details (as much as you know, check the info button at the bottom right of the player)

Video:

Title4K HEVC Dolby Vision Profile 7.6 (HDR10)
CodecHEVC
AVCNo
ProfileMain 10
Level153
Resolution3840x2160
Aspect ratio16:9
AnamorphicNo
InterlacedNo
Framerate23.976025
Bitrate92633 kbps
Bit depth10 bit
Video rangeHDR
Video range typeDOVIWithEL
DV titleDolby Vision Profile 7.6 (HDR10)
DV version major1
DV version minor0
DV profile7
DV level6
DV rpu preset flag1
DV el preset flag1
DV bl preset flag1
DV bl signal compatibility id6
Color spacebt2020nc
Color transfersmpte2084
Color primariesbt2020
Pixel formatyuv420p10le
Ref frames1

Audio:

TitleTrueHD Atmos 7.1 - English - Dolby TrueHD + Dolby Atmos - Default
Languageeng
CodecTRUEHD
AVCNo
ProfileDolby TrueHD + Dolby Atmos
Layout7.1
Channels8 ch
Bitrate4954 kbps
Sample rate48000 Hz
Bit depth24 bit
DefaultYes
ForcedNo
ExternalNo

Subtitle:

TitleEnglish (Forced) - PGSSUB
Languageeng
CodecPGSSUB
AVCNo
DefaultNo
ForcedYes
ExternalNo

Playback path

Transcode

Symptoms (check all that apply)

• Black screen / endless spinner
• Audio only (no video)
• Stuttering / frame drops
• A/V sync issues
• Seeking/scrubbing broken
• Subtitles missing or incorrect
• Unexpected forced transcode
• App crashes / exits

Steps to reproduce

• Have Jellyfin Server (v10.11.9) behind a reverse proxy
• Attempt to play a movie on Moonvin v2.4.0 with with a PGSSUB track

Frequency

Always

Logs / errors (optional)

It throws a gateway timeout every single time, and only for PGSSUB. Other sub formats or no subs at all plays fine. Attempted numerous times throughout the day and always got a 504, yet everything else connects fine. This exact file without the subtrack selected will play correctly.