Found the problem. UE expects you will be playing a video when streaming something in…
in void FStreamingPauseRenderingModule::BeginStreamingPause( FViewport* GameViewport )
is hard coded to
// We started playing a movie
bMovieWasStarted = true;
Solution is to:
GEngine->RegisterBeginStreamingPauseRenderingDelegate(nullptr);
Then set it back after the datalayer is loaded