Save and Quit World Lag

When you click Save & Quit in the Pause Menu it lags for a few seconds and then
the "Saving World" screen (with that chest icon) appears for 1-2 Seconds.
This Screen should appear instantly when you clicked the button.

You can see it in this video: https://www.youtube.com/watch?v=-0TYPH5aa9w&feature=youtu.be