Going to Fullscreen then back to normal enables always the sidebar

[arynvi]

Hi there,
there is a behavior that I find quite irritating: if I go to full screen (using F11) and then I press F11 again then when I am back in normal window the sidebar is enabled, even if it wasn't before going to full screen, so every time I have to press F12 to remove it.

Is this the normal (I mean, intended) way of functioning or am I doing something wrong?

How can I prevent this?

Thanks