When dealing a killing blow to other players using Knockback, they do not actually get knocked back

When a player is shot by arrows, slain by a sword, impaled/speared with a trident, or blown up by various explosions or killed by a tamed wolf, they will not get knocked back. This can also occur when a hostile mob kills a player, the most notable way of seeing this is by being blown up by a creeper near passive mobs (for comparison) and you also have to be in third person front or back to see this. This issue is related to MCPE-19222.