Disabling shields with high atttack frequency will cause an abnormal knock back

If you attack a blocking player too fast, the victim will be knocked back too high. But it doesnt happen when you attack too slow.

What I expected to happen was...:
I dont know whats your purpose to make this knock back, but i think a blocking player should be always knocked back when he/she is hit, or, he/she should be never knocked back.

What actually happened was...:
It will cause a strong upward knock back and a weak backward knock back to the victim when you attack a blocking player too fast.

Steps to Reproduce:
1. A player should block with a shield
2. Another player use an axe to hit this player's shield with a high attack frequency

(To achieve the "high attack frequency", you should use an autoclicker with at least 20 clicks per second.)
3. If you succeed, the victim will be knocked back above 1 block high (If you dont click very fast, the victim will be knocked back only 0.5 block high)

Details:

1. It happens to 1.14+ version.

2. No matter what server or client is, it always happen. (So its truely a vanilla bug)

3. You can only activate it with very high cps, and it only happens when you try to disable one's shield.

Where I think the bug exists:

In order to illustrate that its a bug not a feature, i found this in PaperMC 's source code. (REMEMBER ITS A VANILLA BUG NOT A PAPERMC BUG, I SHOW YOU WITH PAPERMC SRC JUST TO TELL YOU WHERE THE WRONG CODE IS!!!)

net/minecraft/world/entity/LivinEntity.java

1477 ~ 1483

//src
protected void blockUsingShield(LivingEntity attacker){      attacker.blockedByShield(this);
 }

protected void blockedByShield(LivingEntity target){ 
target.knockback(0.5D, target.getX() - this.getX(), target.getZ() - this.getZ(), this);
 } 

Also there are two pictures to show you the bug. 

(2023-03-01_21.14.21.png shows the normal situation)

(2023-03-01_21.14.28.png shows the situation when the bug is activated)

A video to show the bug.

(The 1st hit shows the bug, the 2nd hit shows the normal situation)

(The bricks wall is just for showing how high the victim is knocked back, it doesnt make difference to the bug)

To Dhranios:

sorry but you can download it xD. I cant view it too until i download it

Also this video is not in Vanilla Minecraft because i think you will try it again in your own PC. If it really matters i will add a video in Vanilla Minecraft soon.

New:

The latest vanilla minecraft features an attack delay, so it seems not to be activated in vanilla games. Thanks for your help and please close this issue