File not uploading and some videos thumbnail not show properly.(Black thumbnails)

[KoKoustav]

Some types of video files are not being uploaded to Unlim through Android. Initially, the app shows "synchronization" / "Uploading" in the top left corner, but when clicked, it appears empty and video not uploaded. Additionally, some
videos don't show thumbnails it appears to be as black thumbnails which are not appropriate.

[mindpine-stack]

Uploading an MP4 file from your smartphone (not PC or web) shows the thumbnail properly.