I had a similar situation and the only way I could get files to work for editing in Adobe Premiere Pro was to edit them down “blind.” By this I mean I opened the file in Premiere, cut it into smaller clips and then exported each clip as a separate MP4. Since the files were encoded in Premiere, then Premiere seemed to like them. Hope this helps. I’m not an expert by any means, but maybe this will hold you over till someone more knowledgeable comes along.
Thank you for your response, John. I am following your advice and it’s a lot of work but (A) I hope to get faster someday and (B) it will pay off in the long run!
If anyone else would like to chime in, I would appreciate it.
Could you post a screencap of your screen when you go to File/Export/Media? It could be any number of things, including the source range being improperly selected (I speak from experience).