running Play 2 App in debug mode cant add remote to Debug Port 9999

Using ultimate 2017.1,
Ive looked at multiple threads and forums related to debugging in intellij for an sbt/play app.

Everything works fine if I start the app from my terminal with:
sbt -jvm-debug 9999 run

and then debug with a configured remote in idea.

However, regardless of whether I select debug Play 2 App or if i debug with my own SBT Task with the following extra VM Parameters passed:
-Xdebug
-Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=9999

I cant get the app to run inside intellij with the "Listening for transport dt_socket at address: 9999" to appear. I even tried adding these params to the SBT settings in preferences.

Anyone here had more luck?