When playing VRChat for several hours, sometimes even just over an hour, friends in the menu stop updating. This includes statuses, locations, and even friend requests. I regularly have to use the website to accept friend requests and need to restart my client multiple times a day to be able to join others. This may affect other types of updates as well such as groups.
I'm using Linux and a few other Linux friends report the same issue, however there are a few Windows users who also experience this. Our best guess is that the API websocket doesn't properly reconnect leaving the client in a stale state.