After I fell from a 50 block height in my Survival world and suffered no damage at all, I had to do a mass testing in another world to figure out what was happening.

At first, I thought I had a God mode mod installed in my app, but it turns out that the Feather Falling enchantment is bugged. Not on its own, but only if the boots are enchanted with Protection. Let me explain.

When falling from a 50 block height with normal Feather Falling IV boots, I suffered the usual damage, with only a sliver of my health remaining. I got confused at first as to why it's not bugged on its own, but once I enchanted the boots with Protection, that's where things started to become even more confusing.

I fell from double the height with 100 blocks this time, and normal Feather Falling IV boots ain't gonna cut it, but once I enchanted the boots with Protection I, I somehow miraculously survived the dreaded fall, this time, with only 3 hearts of health taken. And this is just with Protection I. What's weird is that the amplification bug stacks with the other armor pieces. The armor type does not affect this bug, just so you could know. 

I went to the absolute limit fall damage could take, this time falling from a height of 5000 blocks, and this time with a full Protection I netherite armor set with Feather Falling IV boots. When I landed, the unbelievable happened: I survived, with no health taken whatsoever. From a height of 5000 blocks. Five thousand, blocks.

I don't know if this bug is useful or not, but it definitely needs to be fixed, because a major aspect in taking damage where almost everyone has experienced ever since they began playing, is now taken away from the face of Minecraft, just because of this bug.

If you don't believe me, try it out for yourself. In Bedrock 1.16.0.59 beta.