Minecraft wiki entry for Development_versions, associated text: Powder Snow can no longer be placed in positions that already contain other blocks, such as Fence Posts or Iron Bars.
Glow signs are no longer unlit on DX11 and Mobile platforms (MCPE-117524).
Actor selectors no longer allow self selection with cheats disabled (MCPE-92635).
Projectiles now pass through Structure Void blocks (MCPE-103579).
Zombie, Zombie Villager, Husk, Pillager, Vindicator use correct bone to attach shields (MCPE-98606).
Mobs that pick up Shield now place it to their off-hand.
Visitors now drop inventory on death (MCPE-47563).
Improved placement rules for placing blocks on sides of Stair, Slab and Top Snow block.
Controllers are now able to select the "Button Mode" toggle in the Advanced Settings NPC screen in the Jurassic World pack (MCPE-66446).