Question LoadSceneInPlayMode doesn't start the scene [2018.4.31]

I am having problem when trying to load my test scene through loadsceneinplaymode from test script. it doesn't execute awake/start method of behavior within it.

the reason i did this is simply simple setup of the behavior is one i've testing.
and adding enabled test scene in project is not an option as it would pollute the build size.

i've tried basic LoadScene. and it does execute awake and start method just fine.
but when i changed it to unity editor loadscene in play mode the event wont get invoked.

is this intended ?

 

so . again it might also be another of my stupidity. i left the .unity postfix for calling the scene.

would be nice if there are an example in documentation pages