Fopnu 1.29 (Windows 10 64-bit) seems to have a weird bug which causes slow downloads when the user is in the Transfers screen, but the downloads go fast again when the user switches and stays in the Library screen.

To replicate:

Load Fopnu and stay in the Library screen with a number of downloads, say 50. Notice the download speed, say 2 MB/s. Switch to the Transfers screen. Downloads will immediately slow down, say to 300 kB/s. Switch back to the Library screen, downloads will immediately go fast again at 2 MB/s.

Switching to the Bandwidth screen appears to have no effect on download speed. If downloads were slow they remain slow. If fast, they remain fast.

Or maybe not, I saw the download speed randomly slowing down while being in the Library screen... Need to observe this more to understand whether it just happened randomly to change speed the moment I switched screens.