I wonder if you might be confused about the term 'runaround text'? Just to be sure, let me explain (forgive me if you know all this already)...
When you place your circle in front of the text container and make it wrap, the circle effectively pushes the text out of the way. In other words, the text will 'runaround' the circle. You see the effect in magazines all the time: a block of text has a picture placed on top of it, so instead of following it's original block, it becomes indented to make room for the image.
I suspect that the reason your text disappears is because the circle is covering too much of your text container. If there is no space left in the container, there is nowhere for the text to go, so it disappears. The solution is to make the text container larger.
Perhaps, instead, you are trying to make your text follow a circular path? In that case, you need to draw your shape first, then click and HOLD on the text tool until you see a few more tools. One of these allows you to type directly onto a path. Another allows you to type within a path. Try them out to see if they're suitable.