I was working on having a panel autohiding on the right side of the screen, only containing an icon-only task manager, but it doesn't work.

First, it seems to be working fine when maximised. But if I set it to "center", and change its size to a lower value (so to fit only the few icons in it), then it may or may not work.
I've actually managed to make it work once, but then when you start an application, the dock won't hide anymore.

But that's only an exception, because it just doesn't hide at all.

On the contrary, I have a top panel maximised, and this one auto-hides just fine.

Reproducible: Always

Steps to Reproduce:
1. Move the default panel on the right side of the screen;
2. Remove everything, but the task manager and the desktop switcher;
3. Set it to center content, and do not maximise it;
4. Set it to autohide.

Actual Results:  
The panel won't autohide.

Expected Results:  
The panel should correctly auto-hide, even when applications are started.