Why am I unable to use the Spacebar to center the camera on my champion when using Semi-Locked cam?

I was excited to see this camera was added in League of Legends after using it extensively in Heroes of the Storm, but what is unlike Heroes of the Storm is that the spacebar doesn't center the camera onto your character (similar to using it with the camera is completely unlocked).

So in order to center the camera back onto my character, I have to manually adjust the screen using my mouse (or arrow keys, which I never use) in order to perform a new action. For example, if my character were getting attacked by an enemy from somewhere down and left of me, and I had my camera positioned up and right of my character, I would have to manually position the camera back onto my character using my mouse, and would cause a long delay (in League time) before I would be able to perform an action to counter that attack. If I pressed spacebar, I would be able to center the camera back onto myself and defend myself significantly faster.

Just something that irks me about this camera function. I just discovered and started using it today, but it's very inconvenient currently without being able to use the spacebar.