The bug:

The player stays on the water surface (doesn't sink) when holding the 'forward' and 'sprint' keys

How to reproduce:

• Hold 'space' to stay on the water surface
• Start swimming (walking) forwards while holding the 'sprint' key at the same time
• Let go of the 'space' key

You are "walking" on the surface of the water without sinking (the "Y" axis doesn't change)