I've recently started working on an existing objc project and wanted to check the memory graph debugging tool. As I started a debugger with the app I realised it doesn't show in the debugging tools. 

I tried it with another project (created a new swift project) and the icon suddenly did show again. But only for this project.

So my question now is if there're any settings in a particular project that can prevent the memory graph debugging tool from showing?

Any hints are appreciated. 
I tried a lot of different simulators (iOS 9/10/11). I event tried rebooting my macbook because I read somewhere this could help ;-)

I'm using an objc only project with Xcode 9.1 or Xcode 9.2 beta 2.

This is my diagnostics selection in the scheme if that's related: 

[![diagnostic selection](https://i.stack.imgur.com/LPW7D.png)](https://i.stack.imgur.com/LPW7D.png)