I usually run Qucs for delay-simulations. Until now, to my full satisfaction. Here, however, I encounter a - so I think - a wrong plot.
With a maximum delay of 7 ns, the plot shows 8 ns of undefined time, and a seemingly wrong output. When I move the initial time of 0 to 10 ns, everything looks like I'd expect it to look.
I also attach the wrong plot, as reference.