Just noticed on a few rides that there seems to be a power cap at 1200? I have been mindful on a few sprints to check my data.
What did your power meter display during those times (outside of Zwift like on your garmin or srm or whatever you’re using)?
I don’t think so. I hit 1500 on the Green Jersey sprint last week. I have gone over 1200 a couple times before that even on the clockwise route. Now, I question whether I actually hit 1500… but that is another issue. 
I have hit 1575-1743…It seems to flat-line. I hammered those sections as well, and just wouldnt get past 1200.