I do not know if this is actually a new feature that I have just not read about or rather a bug.
I have notice that (at least in races) the zwifter list i the right side only show you the zwifters in your group.
I got two examples:
Here I at the front of the group, but there are two riders in a break away. I am unable to see how big a gap they have as the list just start with me.
Here I am at the back of the group (second to last rider in the group). You can see that I am not near been the last rider in the race, but I am likewise unable to see the group behind us.
This is really annoying in a race situation where you want to know how far behind/in front you are.