Weird character behavior

Version 0.562.0.5620360 (64bit)

Humanoid replication breaks.
I’ve noticed how in my other game the NPC seemed to just stand around and do nothing even though it was supposed to constantly walk towards a random point.
Today I was making a scene and noticed the behavior shown in the video below.

I experience this in Studio and In-Game.

(Here the characters are walking towards a hole which has a teleporter on the bottom which sends them back to the start position)

Expected Behavior
The NPC character walks to the destination.

Actual Behavior
The NPC’s origin gets displaced and it either doesn’t actually walk to the set destination or it starts flying around.

Issue Area: Engine
Issue Type: Replication
Impact: Medium

Date First Experienced: 2023-02-11 08:51:00

Reproduction file:
bug.rbxm (6.9 KB)

This bug can be reproduced in different ways but this produces the most noticeable reaction.

Reproduction Steps:

  1. Make an NPC move to a point using WalkToPoint in a loop (so it keeps trying to move back after being moved)
  2. Make it so the destination is a part
  3. Add a server script to the destination that when touched it changes the NPC’s HumanoidRootPart’s CFrame to a position away from the destination.
  4. Go into run mode (F8).

(Playing normally it seems to work but when pushing the NPC it starts to fly around the map.)

  1. Observe how the NPC is slowly floating off the baseplate.

Transparent part: destination with script that changes CFrame when touched
Smaller part: The new CFrame


We’ve filed a ticket to our internal database, and will follow up when we have news!

Thanks for the report!


This bug still persists in Version 0.564.1.5640444 (64bit)


We will investigate the root cause of this issue.
In case it helps, one way to work around this bug is to use PivotTo in the character’s model instead of manually setting HumanoidRootPart.Position.

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