File status checker for downloaded files. It could be a button that triggers a file scan.
Or just check it right after the download finishes.
And an option to disable resuming of downloads so if a file is paused or connection is lost, restart that file from the beginning.
Problem solved:
On plex media server, when you download a file with transcoding enabled, if you lose connection halfway and then resume the download, the resulting file will be corrupted.
And the files are already verified up what is possible during the download, your issue is something else please open an issue when you have the problem and fill the template if you want an answer.