When you place a block or blocks in survival and then quit to title and come back the blocks are gone and not in your inventory. Also this is version 0.6.0.
Linked issues
duplicates 1
Comments 2

Sorry I'm new just made the account to report these today.
Duplicate of MCPE-1217, please use the search function to see if your bug has already been submitted. Currently over 50% of tickets are being closed as duplicate.