Rubberband AI?

At an endurance race at Spa with the GT3 Corvette I figured out that the AI was waiting for me several times. Feels like rubberband AI. At the end of the race the whole field (except myself) was very close togehther, after 24 laps! I was pitting as leader in lap 13 with 2 others and was able to reach the top again in lap 19 (the leader was just pitting in Lap 22). Finaly I was 40 seconds in front (AI on second highest level).