I'm not exactly sure when it stopped working but roughly sometime in the past few months (within the last few firmware updates).
I've tried Starring and Unstarring Strava segments on the Strava website (or phone app, doesn't matter) and these changes are no longer Synced with my Edge 540. I had a few hundred segments Starred and had to manually Unstar each and every one of them to clear them all (Strava needs to make it easier to manage Favorite Segments). Synced my Edge 540 via wifi and Garmin Express (didn't matter which) and the changed never happen - no Strava Segments are ever added or removed.
Thus the Strava Live Segments feature / widget is now useless.
Can't help but wonder if this has something to do with the silly Strava lawsuit and I really don't care. I just want a feature I paid for to work again!