Freeze when jumping timeline on web browser

[Chaperone]

I made a completely new installation of versions:

• 10.10.3
  
• 10.10.2
  
• 10.9.10
  

Using:

• Docker
  
• Using my Synology NAS
  
• No plugins
  
• Only 2 movies files, one in MP4 and the remuxed MKV
  

No config inside Jellyfin. All the defaults, including the transcoding. Which means "Hardware acceleration: None".
And I get exactly the same behavior on the web browser.

The dockercompose.yml is the following:

Code:

services:
  jellyfin:
    image: jellyfin/jellyfin:10.9.10
    container_name: jellyfin-2
    environment:
      TZ: Europe/Madrid
    group_add:
      - "937"
    volumes:
      - type: bind
        source: /volume1/docker/jellyfin-2/config
        target: /config
        read_only: false
      - type: bind
        source: /volume1/docker/jellyfin-2/cache
        target: /cache
        read_only: false
      - type: bind
        source: /volume1/video
        target: /media
        read_only: false
      - type: bind
        source: /volume1/music
        target: /music
        read_only: false
      - type: volume
        source: exclude
        target: /media/#recycle
        read_only: true
      - type: volume
        source: exclude
        target: /media/#snapshot
        read_only: true
      - type: volume
        source: exclude
        target: /music/#recycle
        read_only: true
      - type: volume
        source: exclude
        target: /music/#snapshot
        read_only: true
    devices:
      - /dev/dri/:/dev/dri/
    restart: unless-stopped
    network_mode: "bridge"
    ports:
      - 8099:8096

volumes:
  exclude:

Any other ideas to try?
Thanks!