How to reproduce:
1. Open attached Unity project "Test Bed copy"
2. Load scene "Scene1"
3. Open Profiler window
4. Enter the play mode
5. Press space to load second scene
6. Wait few seconds and pause play mode
7. Look at the profiler output
8. Expand Update.ScriptRunDelayedDynamicFrameRotate --> CoroutineDelayedCalls --> LoadNextLevel.LoadNextLevelDelayed() [Coroutine: MoveNext]

Expected result: There is no hint, that coroutine from the first scene is still running.
Actual result: The two coroutines appear as though they are a executing as part of the original coroutine.

Reproduced with: 2018.2.0b3, 2018.2.0a9

Note: can't reproduce on 2017, 2018.1 and 2018.2.0a1 - 2018.2.0a8 because of errors.