Telethon: Fail to add thumbnail for uploaded videos

I cannot get video thumbnail displayed. The code used to send out video is standard code in the manual. I tried all possible ways I can find to send the video. Following are the things I have tried:

• send using file path
• upload video and send using uploaded object
• send file without attributes
• set video attributes with 0 width and 0 height
• add proper attributes for the video
• resize the jpeg thumb file with longer edge of 200px and 10kb size
• resize the jpeg thumb file with 200x200px and less than 10kb size
• resize the jpeg thumb file with longer edge of 320px and less than 200kb size

All files are send with supports_streaming=True. If additional attribute is provided, supports_streaming is also set to True in the attributes. Does anyone succeed in upload video files larger than 100 MB with thumbnail?

  await client.send_file(
      username,
      uploaded_file,
      caption=caption,
      attributes=attributes,
      thumb=tmpfile,
      supports_streaming=True)

Sample thumbnail used when calling send_file: