The bug

While flying around using WASD in creative mode the stat increases, but not if the player only moved by a small amount.

How to reproduce

1. Create a scoreboard to track the stat /scoreboard objectives add Fly minecraft.custom:minecraft.fly_one_cm
2. Put it on the sidebar so you see what's happening /scoreboard objectives setdisplay sidebar Fly
3. Tap any of the WASD keys and notice it being stuck at 0, even with key presses longer than a tap
4. Move just enough to have the score jump to a number, sometimes it increments by 24, 28 or other similar value. This happens during one tick.