The auto-hide disfunction is normally caused by one, (or more), of the icons in the Notification Area having displayed a message and then cleared it - you, having missed it, think the taskbar has gone wacko.
Exactly the same problem exists under Win10 - I have it constantly on a system I RDP into and until I click on the usual culprits in the Notification Area the taskbar will not hide, (luckily there is only 2 or 3 icons which are the cause of this effect, so a single LMB click on each will get the taskbar to hide again).
You could find out which ones are the cause of the problem on your computer and turn off notifications for them.