Video preview thumbnail generation fails with certain Blu-ray rips (NOT re-encoded)

Plex Media Server
13

@ChuckPa, the sample @Raelworld provided on that other thread is a good example of this issue.

Here’s a similar one. Fails to generate thumbnails in Plex.

https://ufile.io/9b2idqv8

% ffprobe -select_streams v -show_frames robocop.mkv | grep key_frame=1 | wc -l
58
% ffprobe -skip_frame nokey -select_streams v -show_frames robocop.mkv | grep key_frame=1 | wc -l
7