I exported a 9:16 video (vertical, for Instagram stories) from Premiere Pro 2018, encoded with H.264 and AAC audio, VBR 2 pass.
However, the video shows nothing but black screen on both my Samsung Note9 and iPhone 6, if I play it back in default players. If I use VLC on my Note9, it plays back just fine.
What is the issue of this and how can I fix it?
Many thanks!