The Bug:

Entities other than players will not fall when the level of levitation effect > 127.

Steps to Reproduce:

1. Summon an entity like this: /summon minecraft:cow ~ ~ ~ {Tags: ["test"] }
2. Give it the effect: /effect give @e [tag=test] minecraft:levitation 100 128

Observed Behavior:

The cow flies to sky.

Expected Behavior:

It falls to the ground.