The "Appearance" parameter disappears from the design panel(right panel)

Hey, 👋 community.
I am having trouble seeing the “Appearance” parameter from the right panel (see the picture), which has disappeared. However, if I select only one page, I notice that some properties belonging to “Appearance” are shown at the top. I felt it was pretty like a bug, but I would like to ask if anyone has the same issue. Thanks!