Video Press block editor

I uploaded several videos to VideoPress (paid account) through the VideoPress plugin on WordPress (dashboard area). The videos uploaded successfully, and play just fine. I need to add vtt files. When I attempt to upload my videos using block editor (in order to add vtt), I keep getting a message to the effect that VideoPress made more than 10 attempts to retrieve the video, but we’re unsuccessful. I have tried to add the video through the video block editor through uploading it again, the media library, and URL. All are failures. Please help.