Realm disappears from player list if you're not online for a while

_The original title blamed gamepass for this behavior, as it was a common factor that we noticed from the posts linked below as well as this issue starting to occur in a similar timeframe as gamepass was introduced. However we since had a few non-gamepass ones that reported this issue, so I'm removing it from the title and the rest of the post, just leaving it here as a note in case it might be a lead.

Sometimes, a realm that you're invited to just doesn't show up ingame, eventhough you haven't been uninvited and the realm hasn't expired. After multiple reports and lots of headscratching on the /r/realms subreddit ((1), (2), (3), (4) and many more), we think we were able to pinpoint the issue a little:

• The realm is sometimes only visble while the owner has the game running. Not necessarily on realms, but just has the game open. Some reports indicate that even opening the launcher alone is enough to make the world reappear. 

• The realm sometimes stays around after the owner logged off for about 24 hours, after which it disappears from the list.

• The realm is owned by someone who owns the game through xbox gamepass, not through buying it individually.

Other issues seem to include that that player cannot be invited to servers while they're not online either, so it might be a larger issue related to gamepass at play here.