Player movement stutters and slows when walking on top of boats, but works fine while sneaking

When the player stands on top of a boat, normal walking movement becomes unsmooth, movement speed is reduced and the camera jitters slightly. This issue can also happen when dismounting while holding the forward key(W). However, movement is completely smooth if the player holds the sneak key while moving on the boat.
Steps to Reproduce:

1. Place a boat on water.

2. Stand on top of the boat.

3. Hold forward(W) to walk normally on the boat.

4. Alternatively, dismount from the boat while still holding the W key.

5. Now hold the sneak key and move around on the boat for comparison.
   Observed Results: Normal walking on the boat is slow, choppy and has minor camera jitter. The problem may trigger when dismounting with W held. Sneaking on the boat is completely smooth without any stuttering.
   Expected Results: Player movement should stay smooth at normal walking speed on top of boats, with no jitter whether sneaking or not.