If you can’t find the original .torrent, one way to find it again is to use BiglyBT client’s Swarm Discoveries feature to search its DHT for the exact file size in bytes (of the main media file within). You may be able to find one or more torrents and simultaneous seed them with Swarm Merging too.
As well as the force recheck method others have mentioned, you can also tell BiglyBT to use existing files elsewhere when adding the torrent, which can copy the data onto there for you without risking overwriting the original files.
If you can’t find the original .torrent, one way to find it again is to use BiglyBT client’s Swarm Discoveries feature to search its DHT for the exact file size in bytes (of the main media file within). You may be able to find one or more torrents and simultaneous seed them with Swarm Merging too.
As well as the force recheck method others have mentioned, you can also tell BiglyBT to use existing files elsewhere when adding the torrent, which can copy the data onto there for you without risking overwriting the original files.