Beams and Stems direction
The direction of beams and stems is controlled by selecting the notes you want to affect and typing Shift+B. The selection will be toggled between auto (default), up, and down. 'Auto' means stems are up if the notes are below 3rd line, so the beam direction will change if the notes do.
Note that there are 3 settings, even though only 2 will produce a visible change for any given stem, since 'auto' will be either up or down.
