So I restarted the same race and this happened again when the safety car came out. The problem is when you are between the SC and the leader, and have to overtake the SC. As soon as you pass the SC, the bug kicks in. I tested it by creating a save right when the caution came out, and going back by the SC, multiple times. Happened every time. Then I tried pitting, letting the leader go by to put me a lap down, which let the SC pick up the leader before I got to it. No glitch. I was able to resume speed straight out of the pits and catch the queue. But I was the last one of 5 cars who could (the 2 leaders and 2 lapped cars who also overtook me while I pitted, then me). All the other cars remained scattered around the track doing delta times until the SC ended. They all still had to pass the SC before the leader caught it.
Add that to lapped cars still not getting the wave-around, and my race was not worth finishing.