How to run Visual Studio load test multiple scenario on multiple agent simultaneously?

I have created VS load test and running it on various machine using test agents. I have added multiple scenarios in load test and set constant user load pattern to 1 for each scenario along with the agent on which scenario will run. When I run load test, it only run on one machine and graph shows 1 user.

Why load test not running all the three scenario, despite giving user count?

I have tried many possible ways to find solution but nothing worked. Please help me.