When in multiplayer on a all blocks turn to stone

I will confirm this bug on version 0.80 on iOS. Technically, the bug is that all blocks turn to whatever block type is left-most in the quick-access set of blocks at the bottom of the screen. It happens when you join a world on another device.

I see what Matt sees, also. 0.8.0/iOS. When joining a world on another device over the local network. Whichever block is in the left-most (first) position in the quick-access set is what is deployed/placed. However, the intended object is removed from inventory. Example: Want to put down a rail. Cobblestone is in the first quick-access position. Cobblestone is put down, and rails is removed from inventory.

Duplicate of MCPE-1916