Roblox's physics engine assigns "ownership" of moving parts to specific players. A script might fail if the server does not allow the player to take ownership of a specific map element.
This security feature ensures that changes made by a player on their own screen don't automatically happen for everyone else. For a part grabber to be "FE," it must use RemoteEvents to tell the server to move the object, so all players see the movement. FE Part Grabber
Most scripts utilize specific keybinds for operation: Roblox's physics engine assigns "ownership" of moving parts