Can't open inventory when using custom touch controls

When using the custom control options for touch controls disables the ability to open the inventory via the button by the hotbar. There is an occasional chance for it to open but it rarely happens. Happens even with no texture packs or add-ons.

 

Steps to reproduce:

1. Enable "Customize Controls (Experimental)" in Touch Settings
2. Go into a Minecraft world
3. Attempt to open the Inventory via the button near the hotbar

 

Expected Result:

Player inventory opens

 

Observed Result:

Button visually changes color as if clicked, but the game treats the input as the same as click the rest of the screen.