This is so stupid! EA techs come on like this and give this bullcrap it's stupid. If they can't help then they need to stop posting on forums like this and work on fixing the issue.
anyway I may have found a cause of this issue. Could you gusy please tell me if you Game Center app is working or not ( only a white screen specifically? That is what my GC is doing. ALso, in the setting can you access the Game Center settings.
I believe that the Game Center malfunctioning and not working is the reason nba is not loading fully. I think it is trying to connect to Game Center, but it can't because the app is not working!
i have tried to fix the game center issue but to no avail. It appears to be caused by things releleated to iOS 9 and above.
If you want any proof as to why I think this, it is because I got nba to work one time (only one time unfortunately) as soon as it got to almost there game center said welcome back and it loaded. Later when I went on (Game Center was malfunctioning at this point) it froze as usual and did not connect to Game Center at all.