Put the summary of the bug you're having here

What I expected to happen was...:

When I pressed 4 to switch to 4 on my hotbar, it would then switch to the item that was in the fourth slot on my hotbar.

What actually happened was...:

It did not switch to the fourth slot in my hotbar, and I realized that it doesn't switch when holding space, it works when not holding space.

Steps to Reproduce:

Have 1-3 or 5-9 selected in your hotbar. Hold space and press 4. It seems to only affect me and none of my friends. Holding space and pressing 4 anywhere else works except Minecraft.