When I got in a boat and drove over an 1 block high edge into flowing water level 3 or less, I glitched in the ground. As I got out of the boat, I came back to the surface and the boat glitched into the ground (1 block deep).

What I expected to happen was...:
I could normally drive with a boat.

What actually happened was...:
I glitched into the ground. As I got out of the boat, the boat glitched into the ground.

Steps to Reproduce:

(0. start Minecraft with 1.20 or 1.20.1)
1. Place water on an edge
2. find a block, where the flowing water is level 3 or less
3. drive with a boat on it (from 1 block high)
4. You will glitch into the ground
5. If you dismount, the boat will glitch 1 block deep into the ground