I was following this documentation to debug our SandBox environment from one of our cloud Developer virtual machines, and it was generally working. But when I tried to debug a custom service (API call from PostMan) the debugger did not stop at my breakpoint.

I spent some time and I managed to make it work. The 2 key things were:

• Change IISExpress to IIS in DynamicsDevConfig.xml (https://community.dynamics.com/365/financeandoperations/b/ievgensaxblog/posts/msdyn365fo-how-to-switch-from-iis-express-to-iis-on-development-vm)
• Install PostMan directly on the DEV VM and connect to the local environment in PostMan instead of SandBox. As I have changed the Web.Config file based on the documentation, I am still debugging SandBox although in Postman the Local Dev’s AX is set as environment to use.