I changed the inventory key binding to button 4 (my mouse side button).

What I expected to happen was...:
For the inventory to both open and close when I clicked button 4.

What actually happened was...:
The inventory opened with the first button click, but didn't close on the second click.

Steps to Reproduce:
1. Attach a gaming mouse to PC.

2. Open Minecraft: Java Edition, and create new world.

3. Go to game menu, options, controls, key binds.

4. Scroll down to 'Open/Close Inventory', and mouse-click 'E' on the screen.

5. Press side button on left side of your gaming mouse, and the inventory key should change          from 'E', to 'Button 4'.

6. Resume game, and open inventory, by pressing side button.

7. Try closing inventory, by pressing side button, but it simply won't close.