qBittorrent official forums

Without paying attention to what was updating I accidentally updated Qbittorrent. OOPS!!! Bad move!! Download files are now renamed from the actual file name to something cryptic like "91ad5bf". WTF? How can I get the real file names back??? How is this cryptic file naming supposed to be better??? I can't find anything in options to correct this bizarre problem! A download stalls or doesn't complete and you are left searching through a list of cryptic file names to find it!! Excuse me but the logic of this new naming scheme escapes me!! If it ain't broke DON'T FIX IT!!! In search it doesn't display all the results now either! In your downloads I can't find the previous version that worked splendidly! PLEASE include the previous version 3.3.4 .RPM in your downloads so that I can get back a version that works logically and lock the version. There may be some "under the hood" improvements but the user experience here took a nosedive!

This is definitely NOT the intended behaviour. qBittorrent by default does not rename anything like this, not even in the latest version.
Why would anyone would ever do that?

So, the problem is in your machine.
Which distro do you use? Judging from RPM... is it Fedora?

Have you checked the distro's bugtracker? Maybe it's a bug that they introduced while they packaged the new version?