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 SL - In Service 2019 JUN - 2019 OCT 96.7 SOH
2018 SV - In Service 2019 JAN - Location: Raleigh, NC - 2019 OCT 93.7 SOH
2013 SL - In Service 2013 FEB, Sold 2018 JUN (50,050 mi) - 4 Bars Lost (44,255 mi)