Hello, I am having this exact same issue

Describe the bug

When I play a show with mpv shim I only get two images for the thumbnail preview. I have the trickplay files and they aren't corrupted.

The trickplay images work fine when I play a video through the web ui on chrome and they also work on the Jellyfin Media Player program. I'm running on a windows machine.

For some reason this only happens in some media, in others it works exactly as expected, I can't tell what the difference is. It looks like it's show-dependent, it seems to happen with every episode of, say, Jujutsu Kaisen, but The Office looks fine

To Reproduce
Steps to reproduce the behavior:

Cast a show from Jellyfin to MPV using MPV shim.

Expected behavior

Display the thumbnail images when you hover over the playback bar.

Screenshots

Desktop (please complete the following information):

• OS: Windows 11 Pro
• Version 23H2

Error Messages
2026-02-25 00:30:08,698 [ INFO] trickplay: Collecting trickplay images...
2026-02-25 00:30:08,991 [ INFO] mpv: thumbfast: Received BIF data.
2026-02-25 00:30:08,991 [ INFO] trickplay: Collected 3 trickplay preview images

In the issue I linked someone asked for the config files, so I'm attaching them, I didn't touch much tho (mpv.conf converted to .txt)

conf.json

mpv.txt