Sudden Knockback on Realms

Since the latest changes made to Realms, players frequently experience sudden knockback for no apparent reason.

Steps to reproduce:

1. Walk around in a Realms world.

Expected result:
Nothing happens.

Observed result:
The player suddenly experiences knockback, as if they had collided with a large number of entities.

Note: The knockback spot disappears immediately after it causes the recoil.