if you have a file with the same name, qbittorrent will hash it, if it matches 100% the progress will be 100% and the file status will change to seeding.

if you have the exact same file, same name, same path and yet it always fails to perform a successful check, you will have to create the torrent file again preferably using a different tool/client.

i could be wrong but to me it sounds like you have two different files with the same name, you created the torrent for one and is trying to seed the other.

Switch to the "General" tab, and double check the "Save Path". On more than one occasion I've initially got it wrong and ended up trying to download it one level too deep - e.g. should be ".../here-it-is/" but I've pointed to ".../here-it-is/here-it-is/". This is particularly easy when you've included a directory when you've created a torrent, not just specific files.

If it is incorrect, simply pause the torrent, right-click it, choose 'Set location', then navigate to the correct directory. It can be a bit tricky sometimes. I often choose a completely different directory a level or two higher up first, so I can then drill down cleanly in the correct directory.