Dropping Frames / Stuttering Playback - Direct Play

[z-a-c-h]

Hello! This is my first post in the forum, but I have been using Jellyfin for the better part of a year. I started a movie the other day and noticed the playback looked "off." I'm unsure of the specific issue description, but to me it appears to be skipping frames, or I might more generally describe the playback as "stuttery" or "laggy." 

The above happens inside the Jellyfin Media Player app. I installed it via Flathub, and its version 1.11.1. The app is installed on an HTPC running Debian 12 + Gnome 43.9. My server is running Jellyfin 10.10.3.0.

When opening Jellyfin via Firefox on the same machine, the movie plays perfectly. This leads me to the conclusion that the issue is not with my server or with my HTPC hardware, but with the client app. Are there settings I can adjust that might impact playback / lead to the issue I described?

Here is the specific media info that is giving me trouble (it's in an MKV container):

Code:

Video
Title: 4K HEVC Dolby Vision Profile 8.1 (HDR10)
Codec: HEVC
AVC: No
Profile: Main 10
Level: 150
Resolution: 3840x1600
Aspect ratio: 2.40:1
Anamorphic: No
Interlaced: No
Framerate: 23.976025
Bitrate: 26143 kbps
Bit depth: 10 bit
Video range: HDR
Video range type: DOVIWithHDR10
DV title: Dolby Vision Profile 8.1 (HDR10)
DV version major: 1
DV version minor: 0
DV profile: 8
DV level: 6
DV rpu preset flag: 1
DV el preset flag: 0
DV bl preset flag: 1
DV bl signal compatibility id: 1
Color space: bt2020nc
Color transfer: smpte2084
Color primaries: bt2020
Pixel format: yuv420p10le
Ref frames: 1

Code:

Audio
Title: E-AC3 7.1 - English - Dolby Digital+ - Default
Language: eng
Codec: EAC3
AVC: No
Layout: 7.1
Channels: 8 ch
Bitrate: 1536 kbps
Sample rate: 48000 Hz
Default: Yes
Forced: No
External: No

[gnattu]

Jellyfin Media Player is really bad at playing HDR files, avoid using that.

If you prefer a local player instead of using browser player, try mpv shim: https://github.com/jellyfin/jellyfin-mpv-shim

That one is more powerful and more configurable and handles hdr correctly if you configured it right.