By my understanding this is desired behavior and not a bug. Resolving.
I'm not entirely sure if I'd say this is entirely resolved or not. Optimally you would be able to get world data even if it's not currently loaded in rs client so that you can set it in onStart, however it would mean slightly changing our implementation.
What are your thoughts on
A. An hourly cron job that parses (or simply requests) a list of the currently available worlds and their attributes, and then stores them. We could then provide this list while syncing with our server, and use this list until the list from within the rs client is available.
B. Caching the list of worlds locally after the first time they become available, and using the cache until the list is available from within the rs client. This would work for every run after the first, however it wouldn't work for the first time and it would also make it so the list will be out of date if they haven't ran the client recently.