So the problem mysteriously went away – partially. That is, now I can change the window resolution. However, it used to be that if I disconnected from a session, the next time I connected, the window resolution would be remembered. That doesn’t happen anymore. So each time I connect to the session, I need to reset the window resolution.
I suppose you might still want to see the logs to diagnose the problem. It seems like there’s a lot of unnecessary stuff that would be included if I followed the steps as described in those links provided. In particular, there are a lot of files under ~/.nx and many are quite old. Wouldn’t only the most recent session be relevant?