Power Apps OnStart: Power Automate Flow Takes 10 Extra Seconds After Returning Data

I’m facing a performance issue in Power Apps when calling a Power Automate flow from App.OnStart.

The flow takes around **2 seconds** to execute, as confirmed by the flow run history. The first and last actions in the flow also show timings consistent with this duration.

However, Power Apps Monitor shows that the overall execution takes approximately **12 seconds**, meaning there is an additional delay of around 10 seconds.

The flow returns a JSON response of approximately 183 KB.

I have minimize the data which respond to power apps around 2-3 kb. Even after that time took is same.

In respond to power app I am responding three parameters Positions, My request and User Role.

I have tried with one Parameters ,no improvement, same time took.

**My questions:**

What could cause this additional 10-second delay after the flow finishes executing?

Does Power Apps spend this time receiving, parsing, or processing the JSON response?

How can I identify the exact source of the delay and optimize the app's loading performance?

After few days.............. I did research on my solution and found one point because of that my flow is lagging by 10 seconds.

It is that. When we are creating a Power app respond flow. Last action 'Respond to Power Apps' has one option in setting which is asynchronous. I have turned ON this option. Which causes delay by not sending respond immediately. So after turning it off. It start sending response immediately and time get corrected as flow orginal time 2 sec.