I came here with similar questions that I found already posted here, for example: https://www.uua.org/communications/websites/forum/menus/how-do-i-re-order-links-sidebar-menu
My "About Us" menu appears in alphabetical order in my left sidebar (though all the rest of the menus appear in the left sidebar in the correct order that I set in Appearance-Menus). I have not changed any of the order numbers in page editor.
All the other menus appear in bold in the left sidebar and not indented for sub-pages, though ironically the About Us sub-page menu items *are* properly indented and not-bold.
According to what I'm reading, I will either have to individually update the order of each page in the page editor or find a better widget that actually reflects the menu (does one exist?).
I tried adding a completely different widget to the left sidebar (an audio player), but it didn't even show up. The existing sidebar overrides anything I try to put there. I even tried to remove the left sidebar completely by removing the widget from the left sidebar space on the widgets page. Nothing happened. It's still there. I also tried to remove the "nested pages" navigation menu. And the left sidebar is still there. (Yes, I cleared my cache and tried a different browser.)
Any ideas? It seems completely stuck.