Sometime, when i minimize CB from task button (i'm in W10), the window minimize, but when i want to restore CB is in the bottom-left corner (just a little part of the "titlebar" appear) 
For information, i don't have any 3rd tools who could interfere with CB and happily it only happen sometime
For information, i don't have any 3rd tools who could interfere with CB and happily it only happen sometime