Game resumes a few ticks when opening achievements/statistics from the pause menu in singleplayer

When you pause the game and open the achievements/statistics screen, the game resumes a few ticks when the "downloading stats & achievements" screen appears. Especially when on low fps.

What I expect to happen:
The achievements/statistics screen and "downloading stats & achievements" screen shows without resuming the game

What actually happened:
The game resumes when the "downloading stats & achievements" screen shows" then pauses after the achievements/statistics screen is shown.

To reproduce:
1. Fall, or power a repeating command block that gives you an item every tick. Also open the debug screen and lower your fps into 40 fps and under.
2. Pause
3. Click "Achievements" or "Statistics"
The bug is reproduced. The y coord changes and a pop sound is played after you open one of those screens. It means the game resumes a few ticks.