I actually found a way around this when I was building Carolina Motorsports Park and I have a theory as to why it happens. The start/finish line is at the end of a long straight, kind of close to the first corner on that track so when I was recording my AI, I would be starting from a dead stop and pushing hard to get up to speed, like a normal start but this corner would be treated differently on any lap but the first lap, right? Because the start/finish line is in the braking zone. When the AI should be braking, they're pushing hard and going way wide because when I recorded the AI lap I had to push hard in that particular spot.
Here's what I did to fix it. I moved the start/finish to a point on the track right in the middle of the longest straight. I recorded my AI lap. I then moved the start/finish line back to where it belongs. This fixed the AI for me. On lap 1 they push like normal, but on lap 2 they treated it properly. It didn't seem to mess anything else up either. Might be worth a try.