Play 2.3-M1 and sbt subprojects assets not found

Hi,
I'm testing play2.3 and i'm working with sub projects

I have an issue while running projects with subproject. All subprojects assets are unreachable when project is laucned via (activator '~ run')
When i use activator 'start' it all works ok.

I pushed a minimal project here :
https://github.com/digitalLumberjack/play-2.3-subproject-assets-error

try activator run and see the 404 error on the subproject asset
try activator start to see working project

Thank you