/spreadplayers spawns you in the floor, this causes you to fall through 1 block thick floors upon spawning in, and is generally very silly.

Steps to reproduce: run a valid spreadplayers command

Observe: floorness existing in your legs

Expected result: being on the ground

Observed result: being in the ground

The way it used to work is it would spawn you one block above the highest block at the x and z coordinates it teleported you to, now it spawns you in that block