what controls when submenus open downward vs when they open upward?
Here on the 'don, my 'emojis' submenu typically opens downward (boo - it often goes past the bottom of the screen) on a first try, and upward (yay! always works) on a second try.
Screencaps from a submenu in calendly.com that opens downward (yay! all options visible!) when it's the at the top of a list, but upwards (boo! opens *behind* a spacer that obscures several options).