Beacon beam spinning animation is not smooth when looking at it diagonally

Steps to reproduce this issue:

1. Enter a world

2. Place iron blocks 3x3 on the ground and place a beacon on it.

3. Look at the beam from a diagonal position, use a spyglass to see it more clearly.

Expected result:

The beam spins smoothly, like watching it from vertical position.

Actual result:

The beam twitches.

Note:

I have enabled Vsync while recording this issue.