Play Standalone runs with 80 FPS - Standalone Client runs with 30 FPS

Hello guys,
i’ve been working on some optimizations for my level by following the best-practice guides for performance optimizations. I kept optimizing and testing by starting the level using Play -> Standalone Game. So now i reached the point where the performance of the game is really good, hitting 100 FPS sometimes and on average between 60-80 FPS. The issue here is once i pack up my game as a standalone client and launch it from outside the editor the performance is back to 30-40 FPS which i initially started on. Do you guys have any advises where to start looking at ? I checked already the quality settings and it appears that they are identical, so now i am wondering what i am missing here.