Items in Inventory bar changes after configuring command block

Items in inventory bar changes after entering and exiting command block editing mode.

The inventory bar had empty spaces before a 'give command block' command was given. After entering and exiting the command block interface, three of the spaces were filled with command block.

After entering and exiting the command block interface, the three command blocks were replaced with recently used items (sand, beacon, grass, and command blocks).

Phone: Lenovo A6010
OS: Android 5.0.2
Game Version: 1.0.5