Try having the NPC’s anchored when in server storage and then unanchored them after cframing them to the spawn position. This may not work, but it is worth a try. Additionally, make sure you are moving the NPC’s using PVInstance | Roblox Creator Documentation. While this is not required, I’m saying this because a lot of people still use the deprecated Model | Roblox Creator Documentation, even though PivotTo is more performant and doesn’t require a HumanoidRootPart, or they don’t understand how to move character models and try setting the BasePart | Roblox Creator Documentation property of the HumanoidRootPart itself, which (usually) doesn’t give them the results they want.
You can try using Humanoid | Roblox Creator Documentation to disable the FallingDown and PlatformStandingHumanoidStateType | Roblox Creator Documentation. I am unsure if this will work though because humanoid states can be finicky. However, given that the NPC is controlled by the server it’s worth a shot. You might be able to call the function on the NPC in ServerStorage and have its clones replicate this behavior. However, as I said earlier, humanoid states can be finicky, so you may have to end up calling it for each individual clone’s humanoid you create.
This happens to me sometimes. Before the Humanoid has loaded the Character it may wobble.
(Example of this: When loading in a huge game with a big part count while the loading screen is still present the character is in the game but not the Humanoid, allowing the character to be pushed around.)
How I Fix it
For me, I clone the NPC to a far away part of the map then TP them to the correct location.