I’m using Sonarr and Radarr, both do the same. Whenever a file is found in the Sabnzbd download folder, it’s copied by their post-processing scripts as file.partial~ to an Rclone mount folder on Google Drive. When its finished copying, the file is renamed without the .partial~.
Any file uploaded this way is detected as a binary file by Drive, and is not playable as a video through their web interface. If I use Rclone copy, its detected as a Video.
I’ve got a debug log of the mounted upload if that’s any use?