Help please with rendering issues with DJI action 3

Shotcut is based on the same tech as Kdenlive. You wrote “profiles” but nothing in Shotcut is labeled “profile.” Then, you mention “pick the matching FPS, GOP” but where? You need to start with Video Mode. From your description, your choice for this is wrong, and changing it in Export > Advanced > Video does not fix that. If you choose Automatic, simply add a DJI video first to a new project, and it will set Video Mode automatically. If you want to see your timeline’s video mode, click Output in the top left corner of the timeline and view Properties.