I'm getting 100% cpu usage spikes when using download limit, I'm guessing it's the same problem.
Also managed to get it to crash. Turned download limit on, ran it until 100% cpu usage, turned it off and got this:
Qt has caught an exception thrown from an event handler. Throwing
exceptions from an event handler is not supported in Qt. You must
reimplement QApplication::notify() and catch all exceptions there.
terminate called after throwing an instance of 'asio::system_error'
what(): Transport endpoint is not connected
Window manager warning: Invalid WM_TRANSIENT_FOR window 0x1c0000f specified for 0x1c0000d ().