I hosted a Teams Live Event and captured the video with subtitles for 6 different languages. I was able to upload to Stream and add the 6 subtitle *.vtt files.
There was some pre chit-chat that was captured at the beginning of the video so I used the "trim" feature in Stream to remove it. However, once the video updates, 5 of the 6 languages that have subtitles are missing.
*Note: I have tried to "re-upload" the video, add the *.vtt files and trim but the same thing happens every time. I lose 5 of the 6 translations - and it's different each time.