So Finnally Guy's Today Minecraft Pe 1.17.40 Released It's One More Official Version With Some New Features .
Mojang fixed many bugs and crashes. Also they added some new experimental features. If you have found any bugs or issues you can report on bugs.mojang.com website. Let's help Mojang improve our game!

Experimental Features:

World generation is still under process. Please make backup of your world because they can gone. 

Note that new features are still tweaking. After you active them your world can crash. After world creation you can't turn off experimental features.

Bug fixes:
Performance / Stability
General
Gameplay
Mobs
Blocks
User Interface
Realms
Character Creator

Download Link -