[Looby]

Doesn't the nav unit always display the direction you're
heading at the top of the screen?

Don't know about the Soobie unit, but in general, GPS-based
devices can't determine the direction unless they're moving.
An electronic compass doesn't require motion (or satellites).

My Garmin GPS is amazingly brain-dead in this regard. When
stopped, it immediately forgets what direction it was moving
the instant before it stopped. It then replaces all directional
arrows (e.g., pointers to nearby gas stations) with compass
headings ("1.1 mi N") ...when it just turned off the compass!

...Murphy was an optimist,

Looby