The simulation logs indicate that at the beginning of lap 20 your driver made her own decision to pit. Almost immediately after that you \"cancelled\" the decision.
Do you remember if the \"PIT\" button turned green and said \"PITTING\" when you clicked on it? Or was it already green and did it turn grey?
If the button was already green and it turned grey, then you will have cancelled the pit stop. If you are fairly sure it did turn green, could you please get back to me. Thanks.
Btw, thanks especially for the link and the screenshot!