I have the same issue. It started a few days ago, and since then most of my torrents are stuck trying to connect to the tracker. After waiting for a while some of them manage to connect, but it's very slow and infrequent (like ~3 per hour).
I am also using a VPN, and right after manually switching IP I can connect for like ~5 seconds tops.
I tried fiddling with the qBittorrent settings but nothing seemed to work.