[vbat99]

Except the movie lengh is always 1 min.

If using the VIDEO_TS structure, then the playable file is VIDEO_TS.IFO. So Kodi is polling this file for stream information, and won't find any.

No matter what <fileinfo> <streamdetails> you add, Kodi won't read them from the NFO File. It will read them directly from the video file, so don't waste your time trying to get them correct in the NFO Files.

You are correct, but not quite.
Kodi does read the Stream details from the Nfo, and will show this in the library...

But, Kodi will overwrite this information when the video file is first played.
Tested by changing the duration on an nfo from 150 seconds to 95000.
Refreshed movie in library and then Kodi shows Runtime as 1583 minutes.
Play movie, and Runtime changes back to 2 minutes in Kodi.

Same occurs for Video codec, channels, resolution etc.

Getting this data into the nfo correctly allows users to filter by these entries before playing of the video file occurs.