Knockback broke

Knockback seems to not be working on my world file, this includes moving the file to a BDS or a Realm. We've tested this with up to 15+ different people of different platforms and regions on even other people attempting to host my same world file. 

All forms of receiving knockback are affected by this, explosions, projectiles and obviously direct PvP or mobs hitting you. You don't move at all, but still receive damage.

What's strange about it is that not everyone seems to be affected, nor is it everyone at one time, people will swap in and out of being able to take knockback seemingly at random. It is not related to standing in certain chunks or effect based as we've cleared effects and tried it in several different locations on the world.

Players who are not and who are receiving it are in the same region, same device and same version of the game. This is seemingly (as far as we can tell) not the root issue either.

We also know it's not scoreboard or tag related as we've removed all scoreboards from the world when testing and removed all tags from all players when testing. Knockback seemingly 

To clarify we don't know what caused this (besides simply updating our world and it breaking) Nor do I really have much more info to give, we know it's not addon related as we removed all addons from the world completely and the bug remained. 

https://drive.google.com/file/d/1kpC8GIy8OmL4xemYa3KWbqbP5efJcw-u/view?usp=sharing