Had the same issue, finally found the solution.
To see the Worker Processes icon you have to click on the top level server node not an individual site.
Then you‘ll see all the processes and you can click on any of them to see the currently running pages.
不能在某一个site站点查看，只能在顶层的Server节点查看
Cannot See Worker Processes Icon in IIS
原文：https://www.cnblogs.com/chucklu/p/12718167.html