It also happened on a straight to me, and again... that was at the time when the AMG GT3 was released and that's quite some time ago. I drove it around Nordschleife and after Flugplatz down to schwedenkreuz it suddenly revved up for a short moment as if the clutch was pressed. I had this at the same place again... But then it didn't appear again so I didn't think about it again. Now it started again end of 2018 with other GT3 cars on other tracks. I have to look what TC setting I used.