Reproduction steps:

1. Open "CommandBuffer.EndSample after Submit bug.zip" project*
2. "Window" -> "Frame Debugger" -> "Enable"
3. Select "MoonRenderPipelineAsset.asset" scriptable object in the Project window
4. In the Inspector window, check "Submit Postprocessors Before End Sample" checkbox

Expected Result: "CommandBuffer.BeginSample" groups the Frame Debugger hierarchy
Actual Result: Calling "CommandBuffer.EndSample" after "ScriptableRenderContext.Submit" messes up the Frame Debugger hierarchy

Reproduced with: 2018.1.0b1, 2017.3.0p1, 2017.2.1p1, 2017.1.3f1
Did not reproduce on: 5.6.5f1(Experimental Rendering functions only implemented as of 2017.1)

Note:
Check Edit*