Reproducing Steps:

1. Prepare a superflat world with a surface of blue ice.
   • Preset code: minecraft:bedrock,5*minecraft:stone,5*minecraft:dirt,5*minecraft:sand,87*minecraft:water,3*minecraft:blue_ice;minecraft:frozen_ocean;oceanmonument,biome_1
2. Place a boat on the ground in an arbitrary direction.
3. Get on the boat and hold the W key to accelerate it.

Then, as expected, the boat is running at a very high speed. According to Minecraft Wiki, its maximum speed can reach approximately 60.6 m/s (≈ 218.2 km/h.)

For some low-end computers, such a high speed may cause game to freeze due to chunk loader failures, and the F3 debug screen will show a message "Waiting for chunks..." forever.

We found this issue on Minecraft versions 1.14.x and 1.15.x, while it was not present in 1.13.x versions.

Note: I have attached a demonstration video and a debug report for this bug.