There is an extremely consistent server-client desync (singleplayer world) when using the Riptide enchantment on a Trident in a long-term survival world. I could not reproduce this on a new world, but my existing world with 240 days can do it every time.

The videos below demonstrate the issue well. The water video shows the bubble bar appearing without ever touching the water. The land video shows incorrect fall damage being applied.

Here is another recent example from someone else who is playing 1.21+, due to the visible Days Played counter: https://x.com/i/status/1829118731886153964

With the impending addition of Hardcore, this should be considered a high-priority issue.

To Reproduce

1. Enter my survival world, named Excavation. Download link: https://www.mediafire.com/file/3xj1tqpwyheuamt/Excavation.mcworld/file
2. Switch to the Trident in the hotbar with the Riptide enchantment
3. Set the weather to rain or thunder
4. Move to a body of water at least 2 blocks deep
5. Riptide straight up repeatedly, without entering the water, getting as close to the water as possible
6. Observe the bubbles meter appearing and splash sounds playing, despite never entering the water
7. Move to land
8. Riptide straight up repeatedly, without touching the ground, getting as close to the ground as possible
9. Observe fall damage taken, eventually causing death, despite never touching the ground

Expected Result

The player position is synced between client and server at all times.

Observed Result

The player position is de-synced, causing the game to incorrectly apply damage and underwater effects when the player is still in the air.