What is a bug

The definition of a software 'bug' is:

An unexpected behaviour occurring under a given set of conditions

A 'bug' is when something unusual or unexpected happens when you perform a particular action, and this unexpected behaviour should be repeatable when you or another user creates the same conditions with the same qBittorrent version and operating system. If you do find some errant behaviour the first thing to do is to ensure you are using the latest version available for your operating system, see the news page for which that is.

So if your question is "qBittorrent is slow" or "My downloads disappeared when I press [any alphanumeric key] on my keyboard" are NOT a 'bug' and should not be reported as such by opening a new issue on the 'bug tracker'. Visit the qBittorrent Support Forum and ask the question there, but please use the forum search before starting a new thread, almost every problem has been asked and answered before, so adding another "Not uploading" question simply adds to the forum "noise level".

And please, where ever you report your problem, include the qBittorrent version, the operating system you are using, and any execution log entry relevant to the problem and the library versions (Help -> About -> Libraries).