I haven't had a perfect experience with the app either for my MY13/MY18 vehicles, but it seems to work about 85 pct of the time. If it times out or fails to refresh, I do one of the following:
1. Sign out, then sign back in.
2. Turn on climate control, turn off.
3. Try again the next day.
4. Turn on car, login via head unit and let it connect
#1 works about 50 pct of time. #2 about 40 pct of time (climate command seems to "wake" up the TCU better for some reason)...the other options are random or if I have time.
As recently as late last night it was working fine on both cars. The MY18 is more reliable.
2018 Leaf SV - In Service 2019 January - Location: Raleigh, NC.
2013 Leaf SL - Original In Service 2013 February - Bar Losses: 2016.10.17 - 25,843 Miles -- 2017.06.23 - 32,080 Miles -- 2018.04.10 - 37,000 Miles -- 4th: 2018.09.23 - 44,255 Miles