Thanks 2re for your support. I did some further investigations. These are the results:
1. Playback of Blu-ray disk on my laptop:
- drive connected via USB split cable into two ports of laptop
- same disk
- same .cfg file
- playback via VLC
result:
- playback works - although it takes ~15 seconds to start
2. Playback of DVD on Kodi
- drive connected via USB split cable into two ports of Odroid C2
- setting of forced region code of DVD player: off
- insert DVD and close tray
result:
- drive spins up
- Kodi main menu shows "Disc"
- Kodi shows popup message in upper right corner like "removeable media mounted" [in German] and title of DVD
- in main window of "Disc" it shows - DVD - [next line:] - playback Disc - open/close
- I can click playback and it starts
3. Playback of Blu-ray on Kodi
- drive connected via USB split cable into two ports of Odroid C2
- same .cfg file as on laptop
- region code of Blu-ray set to: B [Europe/Germany] - other regions setting tested as well
- Insert Blu-ray and close tray
result:
- drive spins up
- Kodi main menu shows "Disk"
- Kodi does not show pop-up message in upper right corner
- in main window of "Disc" it shows - open - [next line:] - playback Disc - open/close
- If I click playback nothing happens
- after ~15 seconds disk stops spinning
Summery (my thoughts):
What seems to be working:
- Blu-ray
- Blu-ray drive
- .cfg file
What is suspicious:
- no pop-up message after closing drive with Blu-ray
- massage in "Disc" window are different: "open" [Blu-ray inserted] vs. "DVD" [DVD inserted]
Does this help to trace the issue?
Thanks again for your help
Fasterix