I have encountered the exact same thing and am able to reproduce it 100% of the time (every playtest).
I created a ServerScript
in Workspace
with the following code:
task.wait(5)
print("destroying")
script:Destroy()
This causes a lag spike. Here is the place file:
DestroyServerScriptInWorkspaceLagSpike.rbxl (55.9 KB)
Specs:
CPU: 12th Gen Intel(R) Core™ i3-12100F
Memory: 32.0 GB
GPU: NVIDIA GeForce RTX 2060
OS: Windows 11