I just started experiencing the same. After I ran an update this afternoon and restarted my machine the screen returned with a grey taskbar with only a carrot (^) symbol showing toward the right margin. No other icons are present. When I move the cursor to the grey taskbar area, it changes to the spinning circle icon.
I have performed a CTRL-ALT-DEL to shut down and restart, same condition returns. I cannot WIN+X or any other WIN+ function. The desktop icons remain and the related apps I've tried seem to work however, when I try my "This PC" shortcut, File Explorer opened after a significant delay. Any guidane to getting the taskbar back to operating properly would be appreciated.