Example: Riding 30min non stop (flat out) is recognized as an interval and best effort.
But intervals shows me best efforts for 2h and more as well. But I never rode that long without any brakes (due to traffic or so). A few days ago my BOLT showed up NP263 or so on a lap > 20 minutes. My FTP is set to 240. This was no best effort. Of course not, it was while communing, with 1 or 2 traffic light stops… 
Looks like shorter workouts are handelled different from longer ones. Are they?