I've enabled Intellihide panel and set taskbar to always hide when covered by any window (in fullscreen, too) but sometimes it doesn't hide . I even tried moving windows over it but taskbar didn't hide, then I usually open Solitaire AisleRiot or Quadrapassel to fullscreen but sometimes taskbar doesn't hide, too . Of course in all cases I never placed the cursor lower on the screen right to avoid showing the taskbar (otherwise I'd be reporting an unexisting issue ). Looks like it hides when it wants . But I saw that every time that taskbar doesn't hide by itself I just have to hover over it with cursor, hover away from it and it hides, what ? How can it be called Intelli ?
I've noticed similar issue as well, both on Zorin and Pop!_OS, where the taskbar stays visible when it shouldn't. Luckily the fix is rather simple for me, just quickly hover over the taskbar with the mouse and it'll start working fine. But I don't know what could be causing this or how to fix it permanently. I guess it must be something within Gnome that causes this to glitch sometimes.
Yes, that's how I hide it, too. But it should hide by itself as I set, I wonder where's the problem .