VRChat Version: VRChat Build 1664, SDK 3.8.2
It occurred at least in the current version. I don't remember when it started occurring.
Description of the bug:
If the local player loses ownership of an object to which VRCObjectSync and VRCPickup are attached, the position of it may temporarily revert to the position it was in when the local player acquired ownership.
This occurs when ownership is transferred when VRCObjectSync is active and not when it is sleeping.
It also does not occur without VRCPickup.
The position moves from OnOwnershipTransferred to the next OnDeserialization.
Steps to reproduce (how did you encounter the bug?):
  1. Move an object to which VRCObjectSync and VRCPickup are attached.
  2. Pass its ownership to a remote player while VRCObjectSync is active.
Any extra files? (output logs, screenshots):
I have confirmed this with the Udon below. The log of the run is also attached.