Player sometimes won't move, when pressing W + Ctrl at the same time

When I try to sprint and walk simultaneously (By pressing W and Ctrl at the same time while standing), the player sometimes just doesn't move at all. After 1-2 Seconds the player then runs forward, if both buttons are still pressed.

What I expected to happen was...:
If standing and then pressing W + Ctrl, the player should instantly run forward.

What actually happened was...:
But instead the player sometimes just don't move at all and stays at his position for a few seconds before then running forward.

Steps to Reproduce:
1. Stand where you are.
2. It seems like it would happen more frequently when you recently have opened a Gui, so open and close your inventory.
3. Press and hold Ctrl + W simultaneous, like you would do with a key combination.
4. Sometimes you won't move and instead stay at your position until a few seconds are gone.