I also experience this regularly when I am on my in-lap and just cruising around slowly. If I come to a complete stop, they will keep going, but they still cruise along like they are waiting for me to catch up. It wouldn't be a problem, but a couple of times they have also not slowed down enough to allow me to completely pass and they end up staying exactly next to me and then hit me in the next corner and in one instance I got a penalty for causing a collision.