I came here looking for an answer to this very problem. I just installed qBittorrent 3.3.4 (Windows 10) today, and fired it up. It's working with every torrent I have in my collection - except for any where the tracker is BakaBT. I tried deleting the torrent without deleting file on one and re-added it from here, just to make sure it wasn't something along those lines, and still the tracker status shows "not working." qB 3.3.4 is in the clent whitelist, so I don't understand why it's not working.
Anyone have any ideas what's going on? Can this be fixed?
Edit: Never mind, I managed to fix the problem. Not sure why Baka was particular effected, but I noticed others were reporting a "not working" status as well, which got me to looking further into the issue. I had copied the qB config files from my Windows 7 setup, where I'm migrating away from. Windows 7 called the VPN interface "Local Area Connection 2", and it turns out that Windows 10 calls it "Ethernet 2." Since my config under Advanced was pointing to listen on "Local Area Connection 2," which no longer exists, that explains why things were rapidly going into "not working" mode. Changed it to listen on interface "Ethernet 2," and all seems to be well again.
Just wanted to post this in case anyone else having a similar situation as they move from an earlier Windows to W10 and are searching for causes. :-)