Noob here. I dont understand the sub-races that happen within races. For instance, when I am in a race, a banner shows on the left that there is some time trial, a sprint or a loop. It seems that these have distinct start and stop points within the race, and my time is shown against others in the race. It is never clear to me when these time trials start or stop, I think it has something to do with the banners. But I cant see any indication on the screen that I am in the middle of one, and I cannot see any markers on the maps (like in Zwift Companion) as to where these races-within-the-race occur. They also are not even in the race descriptions!
It feels like there is a secret that others know that I am not in on - (many things in Zwift feel this way when you are new to it BTW)