Details
Players on locally hosted servers, realms and bedrock dedicated servers teleport while being dealt knockback by another player.
Example:
Video: https://youtu.be/CYjgrogqNPQ
Perfect timestamp: 0:56-1:42
Note: the player himself does not jump whatsoever, nor have connection problems. You can test this out to demonstrate the bug.

How to reproduce
1. Get two or more players on a locally hosted server, realms or bedrock dedicated server
2. Allow them to PvP
3. Observe the knockback for any teleportation

Expected Results
The knockback should be smooth, i.e. the player does not teleport - similar to Java Edition prior to 1.9 (when Combat Update has not been added)
Example video: https://youtu.be/_lC_lXNFsss
Note: The server is based on a Java Dedicated Server