This happends on any gui other than the inventory. When you hold down on a stack of items and then let go, it only transfers 1 item over to ex: Chest. You used to be able to do a stack of items at a time, so i know its a bug.
MCPE-30810
item transfering bug
Resolved
Duplicate
0
Thank you for your report!
However, this issue has been closed as a Duplicate of MCPE-30215.
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