Syncplay skip and crash

[Darth Prime]

Hello, I'm new to Jellyfin (less than a week) and I just started to run into some syncplay issues.
User 1 is able to play through the video without any issues.
User 2 (me) gets skipping backwards and forwards after a few minutes of proper sync, then it crashes into a fatal HLS error

Jellyfin server is installed on ubuntu 24.04 Noble.
User 1 is using firefox in Mint
User 2 is using Chrome in Windows

Here is the ffmpg log:

https://pastes.io/jellypaste

Chatgpt (probably not the best source) says I should try these options:
Option 1: Disable Subtitle Overlay in Transcoding

• In Jellyfin settings (under Playback or Client Playback Profile):
  • Set "Subtitle mode" to "None" or "Burn in: Never"
    
  • Or manually deselect PGS subs for affected files
    
• Best fix if you don’t need subtitles burned in
  

Option 2: Remux the file without subtitles
To permanently strip problematic PGS subtitles:
bash
CopyEdit
ffmpeg -i "input.mkv" -map 0 -map -0:s -c copy "no_subs.mkv"

Then replace the original file or use the stripped one in Jellyfin.

Option 3: Avoid overlay filters
If burning subtitles is necessary, try re-encoding them using a safer subtitle format:
bash
CopyEdit
ffmpeg -i "input.mkv" -map 0 -c copy -scodec mov_text "converted.mkv"

…but note that image-based PGS can’t easily be converted to text.

Option 4: Force fresh timestamps
If you must burn the subs and can't remove them, try:
bash
CopyEdit
-fflags +genpts -avoid_negative_ts make_zero -copyts

This can sometimes stabilize broken timestamps.

I'm not sure what to do, can someone help?