Clearing a large area with air using the /fill command so that the void is exposed causes continuous lag spikes when moving above it.
Filling a thin layer of solid blocks right above the void will fix this issue.

I have recorded a video demonstrating this issue: https://youtu.be/rmMFCxF4y_s

How to reproduce:

1. Increase the commandModificationBlockLimit to a very large number:

/gamerule commandModificationBlockLimit 1000000000

2. Clear a large area:

/fill ~ ~64 ~ ~200 -64 ~200 air 

This will take a while to complete and cause an expected and strong lag spike.

3. Move above the void

Observed result: Continuous and strong lag spikes when moving above the cleared area.

Expected result: A strong lag spike once the clearing task has been completed and no further lag spikes when moving above the cleared area.