Upon setting default "Open/Close Inventory Key" to Tab, The game will open, but will not close the inventory due to the "Tab Panel Switching" functionality added in recent updates, causing the game to override closing the inventory of favor of highlighting the crafting book.
Example images below:
Environment
Minecraft Java Vanilla 1.14 Pre-Release 2
(Issue has existed since application of "Tab" panel switching functionality was added)
Windows 10
Duplicates MC-145691