The update system uses an external process to check for updates, and that process takes time to complete. While it seems like it would be simple to just ping the update server and get an answer back “right now”, it doesn’t work that way - especially on networks behind proxy servers. In order to prevent the update system from flooding our servers with requests, it prevents itself from hitting our servers every time Rhino asks. Instead, if Rhino asked within the last hour (or day, for commercial builds), then it waits before it checks again.
For the vast majority of people, this is fine. In fact, if I stopped announcing when new WIPs were available on this forum, and took away the “Check Now” button, you would get a new build “soon enough” (within a few hours). It’s just because you think you should have it “right when I ask” that you’re disappointed.
Every time I’ve looked into the “Check for updates is broken on my computer” report, I have found that it’s not broken, it’s just waiting longer than the user wants. So, while this is irritating, and could be construed as a problem, it’s not one that is floating very high on my priority list.