same issue. I did however remove the app and re installed it.. it didnt disconnect anymore(grey screen while flying), but with the lag, no luck.. i used an old vodafone tablet, no lag... On my brand new nokia 7 plus.... Terrible lag... I tried older version 3.1.5 on nokia and it did not even start the app.. so still having lag.. as for processing power i agree, the tablet i am using is pretty slow.. but handled older go apps flawlesly... I think the resolution of the newer type phones might be asking for too much data from the wifi connection... Older app used 720p whilst the newer app/phones, and correct me if i am wrong, uses/require 1080p.. might me the cause... Good luck.. try an older app would be my next step