Just to note that I'm having the same problem. However, although I've had various problems with the taskbar refusing to hide, or refusing to reappear since installing win11, this issue seems to have appeared over the last few days. Now, periodically, I return to the computer to find that my setting, automatically hide task bar, has been unticked and the taskbar is permanently on. On reading the previous posts, I also realise that it probably coincides with the computers going into sleep. However, there is one major difference: I run two computers, one with a single monitor and one stand-alone. Both are having the same problemm so it's clearly not linked to the dual monitors. Each time I return, I have to re-tick the automatically hide taskbar setting. It is particularly annoying as, with win10, I had the icons set to small. Now this huge fixed taskbar that I can't move to the side out of the way when troublesome, is completely in the way when using various programs, such as word or excel, to name just 2 examples.
As well as a solution to the current problem, I would like to know whether microsoft has any plans to replace the clumsy new taskbar with one that can be shrunk and moved as before.