Are you’re system swapping since Dragonfish with qbittorrent ?
Since dragonfish ZFS ARC is not limited to 50% of memory usage like before, for me this resulted in heavy swap usage after 24H of uptime. I had to set a limit for ZFS cache to 50% of my total RAM like before the upgrade to make everything work again as expected, no more swap, no more WebUI unresponsive etc.